Hanmi Financial Corporation Quarterly report pursuant to Section 13 or 15(d)

Securities - Summary of Investment Securities Available for Sale (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 914,649	$ 749,458
Gross Unrealized Gain	332	4,729
Gross Unrealized Loss	(7,985)	(406)
Estimated Fair Value	906,996	753,781
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,948	9,997
Gross Unrealized Gain		135
Gross Unrealized Loss	(3)
Estimated Fair Value	4,945	10,132
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	641,256	515,169
Gross Unrealized Gain	138	4,260
Gross Unrealized Loss	(5,332)	(188)
Estimated Fair Value	636,062	519,241
Collateralized mortgage obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	100,244	133,632
Gross Unrealized Gain	190	186
Gross Unrealized Loss	(551)	(217)
Estimated Fair Value	99,883	133,601
Debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	99,015	90,660
Gross Unrealized Gain	4	148
Gross Unrealized Loss	(583)	(1)
Estimated Fair Value	98,436	90,807
Total U.S. government agency and sponsored agency obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	840,515	739,461
Gross Unrealized Gain	332	4,594
Gross Unrealized Loss	(6,466)	(406)
Estimated Fair Value	834,381	$ 743,649
Municipal bonds-tax exempt
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	69,186
Gross Unrealized Loss	(1,516)
Estimated Fair Value	$ 67,670