Transfers of Financial Assets and Mortgage Servicing Assets (Loans sold) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Servicing Assets at Fair Value [Line Items]
Net gain on sale	$ 7,795		$ 4,070	$ 16,359
Commercial Portfolio Segment [Member]
Servicing Assets at Fair Value [Line Items]
Proceeds from the sale of loans held for sale	729	[1]	0	12,771
Net gain on sale	145	[1]	0	(229)
Residential Mortgage [Member]
Servicing Assets at Fair Value [Line Items]
Proceeds from the sale of loans held for sale	452,590	[1]	287,132	773,887
Net gain on sale	7,795	[1]	4,070	16,359
Loans sold with servicing rights retained	416,277	[1]	$ 264,292	$ 690,300
Consumer Loan [Member]
Servicing Assets at Fair Value [Line Items]
Proceeds from the sale of loans held for sale	$ 32,900

[1] Additionally, certain consumer loans not originated for sale were sold at cost for cash proceeds of $32.9 million.