Loans - Loans Sales (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total net gains on loan sales		$ 1,341	$ 2,061	$ 4,475	$ 5,354
Corporate loan sales
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sales		2,868	11,833	15,180	46,770
Less book value of loans sold		2,827	11,512	14,811	45,752
Total net gains on loan sales	[1]	41	321	369	1,018
1-4 family mortgage loan sales
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sales		62,576	73,889	193,476	190,544
Less book value of loans sold		61,276	72,149	189,370	186,208
Total net gains on loan sales	[2]	$ 1,300	$ 1,740	$ 4,106	$ 4,336

[1] Net gains on corporate loan sales are included in other service charges, commissions, and fees in the Condensed Consolidated Statements of Income.

[2] Net gains on 1-4 family mortgage loan sales are included in mortgage banking income in the Condensed Consolidated Statements of Income.