Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Mortgage servicing rights	$ 58,377		$ 61,476
Mortgage Servicing Rights (MSR) Impairment (Recovery)	286	$ 2,486
Fair Value, Inputs, Level 2
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Commercial Loans Held-for-sale, Fair Value Disclosure	9,718		12,474
Residential Held-for-sale, Fair Value Disclosure	113,064		108,010
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Commercial Loans Held-for-sale, Fair Value Disclosure	9,718		12,474
Provision for Credit Losses, Commercial Loans held-for-sale	0		(559)
Residential Held-for-sale, Fair Value Disclosure			108,010
Mortgage banking, net			(3,760)
Other Real Estate Owned Fair Value Disclosure	3,291		9,752
Foreclosure / OREO expense, net	(939)		(1,091)
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Impaired loans	54,762		79,270
Provision for Credit Losses, Impaired Loans	(22,703)		(75,194)
Mortgage servicing rights	62,625		73,149
Mortgage Servicing Rights (MSR) Impairment (Recovery)	$ (286)		$ 200