Long-Term Debt (Detail) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Other long-term debt	$ 301,000	$ 435,000
Total	1,543,019,000	1,564,411,000
Less: current portion	(56,041,000)	(6,710,000)
Total long-term debt	1,486,978,000	1,557,701,000
7.25% Senior Notes due 2020
Debt Instrument [Line Items]
Debt carrying amount	400,000,000	400,000,000
3.25% Cash Convertible Senior Notes due 2014
Debt Instrument [Line Items]
Debt face amount	460,000,000	460,000,000
Debt discount	(79,747,000)	(91,212,000)
Cash conversion option derivative at fair value	90,724,000	115,994,000
Debt carrying amount	470,977,000	484,782,000
1.00% Senior Convertible Debentures due 2027
Debt Instrument [Line Items]
Debt face amount	51,188,000	57,289,000
Debt discount	(1,822,000)	(3,720,000)
Debt carrying amount	49,366,000	53,569,000
Term Loan Facility due 2014
Debt Instrument [Line Items]
Debt carrying amount	$ 622,375,000	$ 625,625,000