Valuation And Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ 33,915	$ 33,272	$ 41,397
Charges to expense	6,509	9,754	4,661
Write-offs, payments and other	(4,932)	(9,111)	(12,786)
Ending balance	$ 35,492	$ 33,915	$ 33,272