Net Carrying Amount of Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2015		Dec. 31, 2014
Debt Instrument [Line Items]
Long term debt	$ 1,464,408		$ 1,394,077
Senior Secured Notes
Debt Instrument [Line Items]
Long term debt	712,907		774,030
Convertible Notes | 1.50% Senior Subordinated Notes Due March 15, 2018
Debt Instrument [Line Items]
Long term debt	357,453	[1]	339,943
Convertible Notes | 2.50% Senior Subordinated Notes Due June 2016
Debt Instrument [Line Items]
Long term debt	294,048	[2],[3]	$ 280,104
Variable Funding Notes
Debt Instrument [Line Items]
Long term debt	$ 100,000

[1] Reflects the net debt carrying amount of the 1.50% Convertible Notes in the consolidated balance sheet as of December 31, 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] In March 2016, the Company entered in to a long-term refinancing arrangement with CF ICX LLC and Fortress Credit Co LLC for an aggregate principal amount of $300 million (refer to Note 19 for further details) in which the proceeds are to be used to pay off the 2.50% Convertible Notes. In accordance with ASC 470, as the terms of the refinancing are readably determinable and the term of the credit agreement is five years (scheduled to mature on March 7, 2021), the Company has classified the 2.50% Convertible Notes as long-term debt on its December 31, 2015 consolidated balance sheet.

[3] Reflects the net debt carrying amount of the 2.50% Convertible Notes in the consolidated balance sheet as of December 31, 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.