Acquisitions - Supplemental Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Business Combinations [Abstract]
Net interest income	$ 146,633	$ 143,250
Provision for loan losses	1,044	4,219
Noninterest income	18,783	19,029
Noninterest expense	92,136	92,344
Net income	$ 54,373	$ 52,244
Fully diluted (in usd per share)	$ 1.07	$ 1.03