Basis of Presentation and Significant Accounting Policies Noncontrolling Interest (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($) shares
Successor [Member]
Stockholders' Equity Attributable to Noncontrolling Interest | $	$ 264,110	$ 264,110
Preferred Stock, Shares Outstanding | shares	0	0
Ambac Assurance Corporation [Member]
Preferred Stock, Shares Outstanding | shares	26,411
Preferred Stock, Liquidation Preference, Value | $	$ 660,300
London Interbank Offered Rate (LIBOR) [Member]
Dividend Rate on Auction Rate Preferred Shares	200