Variable Interest Entities Amortization Expense and Tax Credits and Other Tax Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Investments in Qualified Affordable Housing Projects
Amortization expense	$ 640	$ 354	$ 1,143	$ 609
Tax credits and other tax benefits recognized	$ 976	$ 431	$ 1,752	$ 823