Fair Value Measurements, Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	$ 124,915	$ 156,423
Market valuation adjustment	(155)	0
Provision for Credit Losses, Impaired Loans	(7,796)	(17,272)
Mortgage servicing rights	61,341	60,145	$ 63,280
Mortgage Servicing Rights (MSR) Impairment (Recovery)	425	(321)	$ 14,563
Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	0	0
Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	124,915	156,423
Fair Value, Inputs, Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	0	0
Fair Value, Measurements, Nonrecurring [Member]
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	124,915	156,423
Impaired loans	41,891	53,832
Mortgage servicing rights	70,686	66,342
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	0	0
Impaired loans	0	0
Mortgage servicing rights	0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	124,915	156,423
Impaired loans	0	0
Mortgage servicing rights	0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	0	0
Impaired loans	41,891	53,832
Mortgage servicing rights	$ 70,686	$ 66,342