Qualified Affordable Housing (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Investments in qualified affordable housing projects	$ 11,700,000	$ 15,000,000
Open commitments to fund future investments qualifiedd affordable housing projects	0	0
Tax credits to offset amortization expense of investments in affordable housing projects	3,700,000	4,000,000	$ 4,300,000
Noninterest Expense
Schedule of Equity Method Investments [Line Items]
Amortization expense of investments in qualified affordable housing projects	$ 3,300,000	$ 3,600,000	$ 4,100,000