Income Taxes (Details 3) (USD $)	8 Months Ended	12 Months Ended		4 Months Ended	8 Months Ended	12 Months Ended		4 Months Ended	8 Months Ended	12 Months Ended		4 Months Ended	8 Months Ended	12 Months Ended		4 Months Ended
	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Apr. 30, 2010 Predecessor	Dec. 31, 2010 Continuing operations	Dec. 31, 2012 Continuing operations	Dec. 31, 2011 Continuing operations	Apr. 30, 2010 Continuing operations Predecessor	Dec. 31, 2010 Discontinued operations	Dec. 31, 2012 Discontinued operations	Dec. 31, 2011 Discontinued operations	Apr. 30, 2010 Discontinued operations Predecessor	Dec. 31, 2010 Other Comprehensive loss and Equity	Dec. 31, 2012 Other Comprehensive loss and Equity	Dec. 31, 2011 Other Comprehensive loss and Equity	Apr. 30, 2010 Other Comprehensive loss and Equity Predecessor
Valuation allowance
Change in valuation allowance	$ (29,877,000)	$ (256,715,000)	$ 6,486,000	$ (162,458,000)	$ (31,685,000)	$ (234,536,000)	$ (9,283,000)	$ (160,251,000)	$ 215,000	$ (2,763,000)	$ (457,000)	$ (3,708,000)	$ 1,593,000	$ (19,416,000)	$ 16,226,000	$ 1,501,000
Unrecognized tax benefit		$ 43,900,000	$ 48,100,000