Schedule Two, Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Doubtful Accounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of Year	$ 2,765	$ 1,115	$ 1,166
Provision for Doubtful Accounts	3,694	2,736	1,271
Applications	(2,328)	(1,086)	(1,322)
Balance at End of Year	4,131	2,765	1,115
Valuation Allowance of Deferred Tax Assets
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of Year	201,238	256,800	267,804
Provision for Doubtful Accounts		21,138
Applications	(21,865)	(76,700)	(11,004)
Balance at End of Year	$ 171,053	$ 201,238	$ 256,800