Income Taxes Expense from Continuing Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Expenses [Line Items]
Current income tax expense	$ 161,332	$ 169,500	$ 147,346
Deferred income tax expense	75,337	56,666	99,129
Income tax expense	$ 236,669	$ 226,166	$ 246,475