|
Investment Securities - Available for Sale Securities, Continuous Unrealized Loss Position, Fair value (Detail) (USD $)
In Thousands, unless otherwise specified
|
Sep. 30, 2014
Security
|
Dec. 31, 2013
Security
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
$ 4,546
|
$ 10,607
|
| Available-for-Sale Within One Year, Estimated Fair Value |
763,346
|
366,638
|
| Available-for-Sale Within One Year, Number of Securities |
144
|
124
|
| Available-for-Sale More than One Year, Gross Unrealized Loss |
6,689
|
8,362
|
| Available-for-Sale More than One Year, Estimated Fair Value |
181,462
|
107,384
|
| Available-for-Sale More than One Year, Number of Securities |
73
|
45
|
| Available-for-Sale, Gross Unrealized Loss |
11,235
|
18,969
|
| Available-for-Sale, Estimated Fair Value |
944,808
|
474,022
|
| Available-for-Sale, Number of Securities |
217
|
169
|
|
Municipal bonds-taxable [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
9
|
787
|
| Available-for-Sale Within One Year, Estimated Fair Value |
2,238
|
22,817
|
| Available-for-Sale Within One Year, Number of Securities |
2
|
16
|
| Available-for-Sale More than One Year, Gross Unrealized Loss |
138
|
293
|
| Available-for-Sale More than One Year, Estimated Fair Value |
5,511
|
3,813
|
| Available-for-Sale More than One Year, Number of Securities |
5
|
4
|
| Available-for-Sale, Gross Unrealized Loss |
147
|
1,080
|
| Available-for-Sale, Estimated Fair Value |
7,749
|
26,630
|
| Available-for-Sale, Number of Securities |
7
|
20
|
|
U.S. treasury securities [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
1
|
1
|
| Available-for-Sale Within One Year, Estimated Fair Value |
163
|
19,996
|
| Available-for-Sale Within One Year, Number of Securities |
1
|
2
|
| Available-for-Sale More than One Year, Number of Securities |
|
|
| Available-for-Sale, Gross Unrealized Loss |
1
|
1
|
| Available-for-Sale, Estimated Fair Value |
163
|
19,996
|
| Available-for-Sale, Number of Securities |
1
|
2
|
|
Municipal bonds-tax exempt [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
|
30
|
| Available-for-Sale Within One Year, Estimated Fair Value |
|
8,562
|
| Available-for-Sale Within One Year, Number of Securities |
|
5
|
| Available-for-Sale More than One Year, Number of Securities |
|
|
| Available-for-Sale, Gross Unrealized Loss |
|
30
|
| Available-for-Sale, Estimated Fair Value |
|
8,562
|
| Available-for-Sale, Number of Securities |
|
5
|
|
Collateralized mortgage obligations [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
914
|
2,353
|
| Available-for-Sale Within One Year, Estimated Fair Value |
145,816
|
87,026
|
| Available-for-Sale Within One Year, Number of Securities |
30
|
27
|
| Available-for-Sale More than One Year, Gross Unrealized Loss |
805
|
864
|
| Available-for-Sale More than One Year, Estimated Fair Value |
21,188
|
14,657
|
| Available-for-Sale More than One Year, Number of Securities |
9
|
7
|
| Available-for-Sale, Gross Unrealized Loss |
1,719
|
3,217
|
| Available-for-Sale, Estimated Fair Value |
167,004
|
101,683
|
| Available-for-Sale, Number of Securities |
39
|
34
|
|
Mortgage-backed securities [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
2,947
|
3,437
|
| Available-for-Sale Within One Year, Estimated Fair Value |
422,318
|
170,324
|
| Available-for-Sale Within One Year, Number of Securities |
73
|
51
|
| Available-for-Sale More than One Year, Gross Unrealized Loss |
1,764
|
2,589
|
| Available-for-Sale More than One Year, Estimated Fair Value |
60,057
|
30,947
|
| Available-for-Sale More than One Year, Number of Securities |
22
|
12
|
| Available-for-Sale, Gross Unrealized Loss |
4,711
|
6,026
|
| Available-for-Sale, Estimated Fair Value |
482,375
|
201,271
|
| Available-for-Sale, Number of Securities |
95
|
63
|
|
U.S. government agency securities [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
537
|
3,942
|
| Available-for-Sale Within One Year, Estimated Fair Value |
85,948
|
50,932
|
| Available-for-Sale Within One Year, Number of Securities |
22
|
19
|
| Available-for-Sale More than One Year, Gross Unrealized Loss |
3,119
|
3,374
|
| Available-for-Sale More than One Year, Estimated Fair Value |
71,843
|
32,606
|
| Available-for-Sale More than One Year, Number of Securities |
26
|
12
|
| Available-for-Sale, Gross Unrealized Loss |
3,656
|
7,316
|
| Available-for-Sale, Estimated Fair Value |
157,791
|
83,538
|
| Available-for-Sale, Number of Securities |
48
|
31
|
|
SBA loan pool securities [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
27
|
|
| Available-for-Sale Within One Year, Estimated Fair Value |
87,088
|
|
| Available-for-Sale Within One Year, Number of Securities |
15
|
|
| Available-for-Sale More than One Year, Gross Unrealized Loss |
673
|
969
|
| Available-for-Sale More than One Year, Estimated Fair Value |
12,037
|
12,629
|
| Available-for-Sale More than One Year, Number of Securities |
4
|
4
|
| Available-for-Sale, Gross Unrealized Loss |
700
|
969
|
| Available-for-Sale, Estimated Fair Value |
99,125
|
12,629
|
| Available-for-Sale, Number of Securities |
19
|
4
|
|
Corporate bonds [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
|
9
|
| Available-for-Sale Within One Year, Estimated Fair Value |
|
5,024
|
| Available-for-Sale Within One Year, Number of Securities |
|
1
|
| Available-for-Sale More than One Year, Gross Unrealized Loss |
89
|
177
|
| Available-for-Sale More than One Year, Estimated Fair Value |
7,902
|
11,803
|
| Available-for-Sale More than One Year, Number of Securities |
2
|
3
|
| Available-for-Sale, Gross Unrealized Loss |
89
|
186
|
| Available-for-Sale, Estimated Fair Value |
7,902
|
16,827
|
| Available-for-Sale, Number of Securities |
2
|
4
|
|
Other securities [Member]
|
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-Sale Within One Year, Gross Unrealized Loss |
111
|
48
|
| Available-for-Sale Within One Year, Estimated Fair Value |
19,775
|
1,957
|
| Available-for-Sale Within One Year, Number of Securities |
1
|
3
|
| Available-for-Sale More than One Year, Gross Unrealized Loss |
101
|
96
|
| Available-for-Sale More than One Year, Estimated Fair Value |
2,924
|
929
|
| Available-for-Sale More than One Year, Number of Securities |
5
|
3
|
| Available-for-Sale, Gross Unrealized Loss |
212
|
144
|
| Available-for-Sale, Estimated Fair Value |
$ 22,699
|
$ 2,886
|
| Available-for-Sale, Number of Securities |
6
|
6
|