Servicing Advance Liabilities - Summary of Servicing Advance Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Summary of Servicing Advance liabilities Table [Line Items]
Servicing advance liabilities	$ 1,365,885	$ 971,286
Servicing Advance Facilities [Member]
Summary of Servicing Advance liabilities Table [Line Items]
Servicing advance liabilities	1,197,148	67,905
Early Advance Reimbursement Agreement [Member]
Summary of Servicing Advance liabilities Table [Line Items]
Servicing advance liabilities	$ 168,737	$ 903,381