Consolidated Statements Of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	7 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011	May 31, 2010	May 31, 2009
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (5,565)	$ 73,609	$ 62,870	$ 26,022
Unrealized gain (loss) on marketable securities, net of tax	(1)	(3)	63	(19)
Derivatives:
Unrealized (loss) gain on derivative financial instruments	1,661	(5,781)	0	0
Reclassification adjustment for loss included in net income	342	2,024	0	0
Tax effect	(776)	1,463	0	0
Unrealized (loss) gain on derivative financial instruments, net of tax	1,227	(2,294)	0	0
Foreign currency translation adjustment	1,063	(578)	0	0
Total comprehensive income (loss)	$ (3,276)	$ 70,734	$ 62,933	$ 26,003