Nature of Business and Basis of Presentation (Details) $ in Thousands		3 Months Ended		9 Months Ended
	Nov. 02, 2015 USD ($)	Dec. 31, 2013 USD ($)	Jun. 30, 2013 USD ($) agreement	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
PMIERs tables expected review period				2 years
Notice period for updates to PMIERs tables				180 days
(Increase) decrease in restricted cash		$ 42,900	$ (60,300)	$ 17,212	$ 233
Number of agreements entered into to resolve disputes | agreement			2
Senior Notes, interest at 5.375% per annum, due November 2015 | Subsequent Event
Debt Instrument [Line Items]
Repayments of debt	$ 61,900