Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Schedule of Restricted Stock Awards (Detail)

v3.2.0.727
Share-Based Compensation - Schedule of Restricted Stock Awards (Detail) - Jun. 30, 2015 - Restricted stock awards [Member] - $ / shares
Total
Total
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]    
Number of Shares, Restricted stock at beginning of period 175,072 173,222
Number of Shares, Restricted stock granted 49,334 53,184
Number of Shares, Restricted stock vested (16,151) (18,151)
Number of Shares, Restricted stock forfeited (15,000) (15,000)
Number of Shares, Restricted stock at end of period 193,255 193,255
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]    
Weighted-Average Grant Date Fair Value Per Share, Restricted stock at beginning of period (in usd per share) $ 19.55 $ 19.58
Weighted-Average Grant Date Fair Value Per Share, Restricted stock granted (in usd per share) 22.59 22.43
Weighted-Average Grant Date Fair Value Per Share, Restricted stock vested (in usd per share) 22.26 22.50
Weighted-Average Grant Date Fair Value Per Share, Restricted stock forfeited (in usd per share) 21.83 21.83
Weighted-Average Grant Date Fair Value Per Share, Restricted stock at end of period (in usd per share) $ 19.92 $ 19.92
Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period   3 years
Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period   5 years