Company's Debt Maturities on Calendar Year Basis (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Debt Instrument [Line Items]
Total	$ 1,411,122		$ 1,427,319
July 1 through December 31, 2014	32,264
2015	61,250
2016	334,546
2017	61,250
2018	392,813
Thereafter	528,999
1.50% Convertible Notes
Debt Instrument [Line Items]
Total	331,563	[1]	323,418
2018	331,563	[1]
2.50% Convertible Notes
Debt Instrument [Line Items]
Total	273,296	[2]	267,013
2016	273,296	[2]
Senior Secured Notes
Debt Instrument [Line Items]
Total	806,263		836,888
July 1 through December 31, 2014	32,264
2015	61,250
2016	61,250
2017	61,250
2018	61,250
Thereafter	$ 528,999

[1] Reflects the net debt carrying amount of the 1.50% Convertible Notes in the consolidated balance sheet as of June 30, 2014, in accordance with accounting for convertible notes. The principal amount owed to the holders of the 1.50% Convertible Notes is $400.0 million.

[2] Reflects the net debt carrying amount of the 2.50% Convertible Notes in the consolidated balance sheet as of June 30, 2014, in accordance with accounting for convertible notes. The principal amount owed to the holders of the 2.50% Convertible Notes is $300.0 million.