Company's Debt Maturities on Calendar Year Basis (Detail) - USD ($) $ in Thousands		Jun. 30, 2015		Dec. 31, 2014
Debt Instrument [Line Items]
Total		$ 1,478,585		$ 1,394,077
2015		30,562
2016		347,918
2017		61,123
2018		509,444
2019		61,123
Thereafter		468,415
Senior Secured Notes
Debt Instrument [Line Items]
Total		743,469		774,030
2015		30,562
2016		61,123
2017		61,123
2018		61,123
2019		61,123
Thereafter		468,415
Convertible Notes | 1.50% Senior Subordinated Notes Due March 15, 2018
Debt Instrument [Line Items]
Total		348,321	[1]	339,943
2018	[1]	348,321
Convertible Notes | 2.50% Senior Subordinated Notes Due June 2016
Debt Instrument [Line Items]
Total		286,795	[2]	$ 280,104
2016	[2]	286,795
Variable Funding Notes
Debt Instrument [Line Items]
Total		100,000
2018		$ 100,000

[1] Reflects the net debt carrying amount of the 1.50% Convertible Notes in the consolidated balance sheet as of June 30, 2015, 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, 2015, in accordance with accounting for convertible notes. The principal amount owed to the holders of the 2.50% Convertible Notes is $300.0 million.