Mortgage Servicing Rights - Changes in Residential and Securitized Mortgage Servicing Rights (Details) (USD $) In Thousands, unless otherwise specified			3 Months Ended				9 Months Ended				3 Months Ended	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Mortgage Servicing Rights Residential		Sep. 30, 2013 Mortgage Servicing Rights Residential		Sep. 30, 2014 Mortgage Servicing Rights Residential		Sep. 30, 2013 Mortgage Servicing Rights Residential		Sep. 30, 2013 Securitized Mortgage Servicing Rights	Sep. 30, 2013 Securitized Mortgage Servicing Rights
Servicing Assets at Fair Value [Line Items]
Carrying value, beginning of period	$ 237,221	$ 241,018	$ 228,815		$ 214,959		$ 241,018		$ 144,520		$ 97	$ 193
Additions			9,637		18,725		23,620		73,398
Due to changes in valuation assumptions			13,583		6,589		13,091		54,437
Increase (decrease) in fair value, due to other changes			(14,814)	[1]	(12,168)	[1]	(40,508)	[1]	(44,250)	[1]
Amortization											(97)	(193)
Carrying value, end of period	$ 237,221	$ 241,018	$ 237,221		$ 228,105		$ 237,221		$ 228,105

[1] Net servicing cash flows, including loan payoffs, and the passage of time.