Details of One Point Five Zero Percent Convertible Notes Reflected on Condensed Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Net debt carrying amount	[1]	$ 1,013,318	$ 1,254,160
Convertible Notes | 1.50% Senior Subordinated Notes Due March 15, 2018
Debt Instrument [Line Items]
Equity component carrying amount		48,767	48,767
Unamortized discount		64,121	17,531
Net debt carrying amount	[2]	$ 230,929	$ 277,518

[1] Carrying amounts include aggregate unamortized debt discount and debt issuance costs.

[2] During FY 2016, the Company repurchased a total of $104.9 million par value (of which $51.7 million and $53.2 million were purchased in June 2016 and July 2016, respectively) of the 1.50% Convertible Notes. During the Current Quarter, the Company repurchased a total of $58.9 million par value of the 1.50% Convertible Notes. See below for further details.