Classification of Net Deferred Income Tax Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]
Net deferred income tax assets	$ 506,039	$ 542,818
Prepaid expenses and other current assets
Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]
Net deferred income tax assets	253,664	110,422
Other noncurrent assets
Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]
Net deferred income tax assets	374,667	473,832
Accrued liabilities
Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]
Net deferred income tax assets	(152)	(194)
Other noncurrent liabilities
Balance Sheet Classification of Deferred Income Tax Assets and Liabilities [Line Items]
Net deferred income tax assets	$ (122,140)	$ (41,242)