Parent Company Condensed Financial Information - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Cash	$ 155,489	$ 117,152	$ 139,486	$ 99,399
Other assets	88,725	95,799
Total Assets	7,252,221	7,060,255
LIABILITIES
Other liabilities	38,222	65,252
Total Liabilities	6,316,460	6,176,224
Total Shareholders’ Equity	935,761	884,031	841,956	792,237
Total Liabilities and Shareholders’ Equity	7,252,221	7,060,255
Parent Company
ASSETS
Cash	8,869	21,310	$ 17,057	$ 12,595
Investments in bank subsidiary	925,286	857,293
Investments in nonbank subsidiaries	15,479	19,569
Other assets	8,458	7,272
Total Assets	958,092	905,444
LIABILITIES
Long-term debt	20,619	20,619
Other liabilities	1,712	794
Total Liabilities	22,331	21,413
Total Shareholders’ Equity	935,761	884,031
Total Liabilities and Shareholders’ Equity	$ 958,092	$ 905,444