Business Combinations - Pro Forma Information (Details) - Presidio bank - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018
Pro Forma Information
Net interest income	$ 163,555	$ 160,044
Provision for loan losses	870	7,694
Noninterest income	11,291	10,795
Noninterest expense	92,708	97,563
Income before income taxes	81,268	65,582
Income tax expense	23,730	17,549
Net income	$ 57,538	$ 48,033
Net income per share - basic (in dollars per share)	$ 0.98	$ 0.84
Net income per share - diluted (in dollars per share)	$ 0.96	$ 0.83