Other Noninterest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other noninterest expense [Abstract]
Lending and other client related processing costs	$ 23,768	$ 19,867	$ 15,944
Telephone	10,647	9,793	9,398
Data processing services	10,251	9,014	7,316
Dues and publications	3,263	2,828	2,476
Postage and supplies	2,797	2,851	3,154
Other	21,419	17,890	19,999
Total other noninterest expense	$ 72,145	$ 62,243	$ 58,287