Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Reclassifications out of accumulated other comprehensive income
(Losses) gains on investment securities available-for-sale	$ (680)	$ (1)	$ (680)	$ 279
Income before income taxes	39,660	24,042	76,403	45,620
Income tax expense	(9,425)	(5,516)	(18,062)	(10,676)
Unrealized gains and losses on available-for-sale securities | Amount Reclassified from Accumulated Other Comprehensive Income
Reclassifications out of accumulated other comprehensive income
(Losses) gains on investment securities available-for-sale	(680)	(1)	(680)	279
Income before income taxes	(680)	(1)	(680)	279
Income tax expense	(164)	0	164	(65)
Net income	$ (516)	$ (1)	$ (516)	$ 214