Summary of Significant Accounting Policies (Variable Interest Entities) (Details 1) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Unfunded commitments to fund low-income housing partnerships	$ 18,107
Other Assets
Variable Interest Entity [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	$ 77,500	$ 78,900
Other Liabilities
Variable Interest Entity [Line Items]
Unfunded commitments to fund low-income housing partnerships		$ 16,200
Low-income housing partnerships
Variable Interest Entity [Line Items]
Period over which tax credits or benefits are generally recognized (in years)	10 years
Solar energy partnerships
Variable Interest Entity [Line Items]
Period over which tax credits or benefits are generally recognized (in years)	6 years