Long-Term Debt (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Debt Instrument [Line Items]
Long-term debt	$ 1,781,529	$ 1,376,259	$ 1,492,429
Less current portion	236,640	87,776	146,602
Long-term debt, noncurrent	1,544,889	1,288,483	1,345,827
5% Senior Notes
Debt Instrument [Line Items]
Long-term debt	500,000
7 1/4% Senior Notes
Debt Instrument [Line Items]
Long-term debt		245,237	244,817
Bank debt
Debt Instrument [Line Items]
Long-term debt	1,281,529	1,131,022	1,247,612
Bank debt | Revolving loans
Debt Instrument [Line Items]
Long-term debt	160,000		462,839
Bank debt | U.S. term loans
Debt Instrument [Line Items]
Long-term debt	520,000	520,000	400,000
Bank debt | Canadian term loans
Debt Instrument [Line Items]
Long-term debt	78,400	79,323	82,296
Bank debt | Euro term loans
Debt Instrument [Line Items]
Long-term debt	416,874	433,825	179,812
Bank debt | Other foreign bank revolving and term loans
Debt Instrument [Line Items]
Long-term debt	$ 106,255	$ 97,874	$ 122,665