Derivative Instruments and Hedging Activities Schedule of Interest Rate Swap Receivers Associated with TBA Contracts and MSRs (Details) (Interest Rate Risk Associated with TBAs and MSR [Member], Short [Member], Interest Rate Swap [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Derivative, Notional Amount	$ 1,604,000	$ 1,055,000
Derivative Maturity Over Four Years From Balance Sheet Date [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 1,604,000	$ 1,055,000
Derivative, Average Fixed Interest Rate	2.134%	1.736%
Derivative, Average Variable Interest Rate	0.235%	0.239%
Derivative, Weighted Average Remaining Maturity	6.872	5.654