Fair Value Measurements - Significant Unobservable Inputs used in Fair Value Measurement (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014		Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
Mortgage servicing rights
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 237,221		$ 241,018	$ 228,105	$ 144,520
Valuation Technique	Discounted Cash Flow
Weighted Average Constant Prepayment Rate	8.40%	[1]
Weighted Average Discount Rate	10.00%
Interest rate lock commitments
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 2,180		$ 258	$ 6,190	$ 21,446
Valuation Technique	Discounted Cash Flow
Weighted Average Closing Ratio	72.94%

[1] Represents annualized loan repayment rate assumptions.