Income Taxes Income Taxes - Effect of Income Taxes on Net Income and Stockholders' Equity (Details) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2013	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Successor [Member]
Income Tax Expense (Benefit) [Roll Forward]
Income tax expense (benefit)		$ 7,514	$ 17,364	$ 9,557
Net Unrealized Losses On Securities Tax Effect		(14,669)	(55,906)	88,411
Valuation Allowances And Reserves Charged To Equity		4,081	71,774	(73,018)
Unrealized Loss on FX Tax Effect		14,953	(15,628)	(15,108)
Change in Retirement Benefits Tax Effect		$ 3,797	$ (240)	$ (285)
Predecessor [Member]
Income Tax Expense (Benefit) [Roll Forward]
Income tax expense (benefit)	$ 755
Net Unrealized Losses On Securities Tax Effect	(227,945)
Valuation Allowances And Reserves Charged To Equity	(219,341)
Unrealized Loss on FX Tax Effect	7,010
Change in Retirement Benefits Tax Effect	$ 1,594