Schedule II - Valuation and Qualifying Accounts (Detail) (Allowance for Doubtful Accounts [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 9,174	$ 15,663	$ 9,175
Charged to Expenses	63,928	67,640	56,818
Write-offs	(70,751)	(74,129)	(50,330)
Balance at End of Period	$ 2,351	$ 9,174	$ 15,663