Details of One Point Five Zero Percent Convertible Notes Reflected on Condensed Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long term debt	[1]	$ 1,351,262	$ 1,449,392
Convertible Notes | 1.50% Senior Subordinated Notes Due March 15, 2018
Debt Instrument [Line Items]
Equity component carrying amount		49,784	49,931
Unamortized discount		29,014	42,547
Long term debt	[2]	$ 319,256	$ 357,453

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

[2] In June 2016, the Company repurchased $51.7 million par value of the 1.50% Convertible Notes. See below for further details.