Other Assets Tax Credits Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
Other Assets Tax Credits Narrative (Details) - USD ($)	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Investment Holdings [Line Items]
Investment in Limited Partnerships	$ 3,881,000		$ 3,881,000		$ 3,215,000
Impairment of tax credit investments	3,314,000	$ 0	3,520,000	$ 0
BOC Investment, LLC \| Historic Rehabilitation Tax Credits
Investment Holdings [Line Items]
Investment in Limited Partnerships	169,000		169,000		578,000
Tax Credit Benefits Recognized	3,600,000
Impairment of tax credit investments	3,200,000
Mitchell Street Apartments Investment, LLC \| Historic Rehabilitation Tax Credits
Investment Holdings [Line Items]
Investment in Limited Partnerships	130,000		130,000
Estimated Capital Contributions	5,500,000		5,500,000
Tax Credit Benefits Recognized			$ 0
Tax Credit Benefit Recognized, Period for Recapture			5 years
Rimrock Road Investment Fund, LLC \| New Market Tax Credits
Investment Holdings [Line Items]
Investment in Limited Partnerships	7,200,000		$ 7,200,000		$ 7,500,000
New Market Tax Credit Benefit, Period of Recognition			7 years
Federal New Market Tax Credits Not Yet Recognized	$ 1,900,000		$ 1,900,000
Tax Credit Benefits Recognized			$ 281,000	$ 281,000