Variable Interest Entities (Summary of the Impact of Qualifying LIHTC Investments) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Low income housing tax credits [Member]
Variable Interest Entity [Line Items]
Amortization of qualifying LIHTC investments	$ 2,298,000	$ 2,180,000
Affordable Housing Tax Credits and Other Tax Benefits	(2,523,000)	(2,363,000)
Other tax benefits related to qualifying LIHTC investments [Member]
Variable Interest Entity [Line Items]
Affordable Housing Tax Credits and Other Tax Benefits	$ (1,110,000)	$ (844,000)