Fair Value Measurement Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets and Liabilities Measured at Fair Value on a Non-recurring Basis
Loans held for sale	$ 156,423	$ 64,738
Mortgage servicing rights	60,145	63,280	45,949
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	156,423	64,738
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	156,423	64,738
Impaired Loans	83,956	88,049
Mortgage servicing rights	66,342	74,444
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	156,423	64,738
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	83,956	88,049
Mortgage servicing rights	$ 66,342	$ 74,444