Valuation and Qualifying Accounts (Detail) - Allowance For Doubtful Accounts - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	[1]	$ 8,738	$ 12,140	$ 11,994
Additions Charged to Costs and Expenses	[1]	25,128	9,627	9,718
Deductions	[1]	(25,481)	(13,029)	(9,572)
Balance at End of Period	[1]	$ 8,385	$ 8,738	$ 12,140

[1] These amounts include reserves for bad debts