Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassifications out of accumulated other comprehensive income
Gains on investment securities available-for-sale	$ 0	$ 280
Income before income taxes	36,743	21,578
Income tax expense	(8,637)	(5,160)
Unrealized gains and losses on available-for-sale securities | Amount Reclassified from Accumulated Other Comprehensive Income
Reclassifications out of accumulated other comprehensive income
Gains on investment securities available-for-sale	0	280
Income before income taxes	0	280
Income tax expense	0	(67)
Net income	$ 0	$ 213