Compensation Plans - Reclassifications Out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Noninterest income	$ 18,506	$ 12,629	$ 9,960	$ 13,408	$ 14,418	$ 13,564	$ 11,964	$ 9,230	$ 54,503	$ 49,176	$ 38,347
Net interest income	77,446	63,354	65,833	63,368	61,613	63,046	61,715	52,343	270,001	238,717	191,905
Income before income tax expense	35,439	22,379	18,290	15,839	36,336	36,538	22,903	20,259	91,947	116,036	104,577
Income tax expense	6,508	4,428	3,656	2,971	7,246	7,469	4,479	4,103	17,563	23,297	15,360
Net income	$ 28,931	$ 17,951	$ 14,634	$ 12,868	$ 29,090	$ 29,069	$ 18,424	$ 16,156	$ 74,384	$ 92,739	$ 89,217