Schedule I Condensed Parent Company Financial Statements (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current assets:
Cash and cash equivalents	$ 515,164	$ 673,092	$ 100,415	$ 139,505
Prepaid expenses and other	10,470	13,913
Total current assets	750,118	1,112,481
Deferred financing costs, net of accumulated amortization of $283 and zero, respectively	50,214	54,847
Total assets	2,366,123	2,551,934
Current liabilities:
Accrued liabilities	41,021	37,194
Total current liabilities	190,253	339,607
Shareholders' equity:
Preference shares, $0.01 par value; 200,000,000 authorized shares; zero issued at December 31, 2012 and 2011
Common shares, $0.01 par value; 2,000,000,000 authorized shares; 391,423,703 and 390,530,946 issued at December 31, 2012 and 2011, respectively	3,914	3,905
Additional paid-in capital	1,712,880	1,629,453
Accumulated deficit	(683,176)	(616,148)
Accumulated other comprehensive income	3,685	3,522
Treasury stock, at cost, 2,731,941 and 649,818 shares at December 31, 2012 and 2011, respectively	(8,397)	(6)
Total shareholders' equity	1,028,906	1,020,726	(614,411)	(217,856)
Total liabilities and shareholders' equity	2,366,123	2,551,934
Parent company
Investment in subsidiaries (as a percent)	100.00%
Current assets:
Cash and cash equivalents	132,574	352,872		51,224
Receivables from subsidiaries	373
Prepaid expenses and other	375	394
Total current assets	133,322	353,266
Investment in subsidiaries at equity	888,473	668,618
Deferred financing costs, net of accumulated amortization of $283 and zero, respectively	7,992
Total assets	1,029,787	1,021,884
Current liabilities:
Accounts payable to subsidiaries		1,158
Accrued liabilities	881
Total current liabilities	881	1,158
Shareholders' equity:
Common shares, $0.01 par value; 2,000,000,000 authorized shares; 391,423,703 and 390,530,946 issued at December 31, 2012 and 2011, respectively	3,914	3,905
Additional paid-in capital	1,712,880	1,629,453
Accumulated deficit	(683,176)	(616,148)
Accumulated other comprehensive income	3,685	3,522
Treasury stock, at cost, 2,731,941 and 649,818 shares at December 31, 2012 and 2011, respectively	(8,397)	(6)
Total shareholders' equity	1,028,906	1,020,726
Total liabilities and shareholders' equity	$ 1,029,787	$ 1,021,884