Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 324,648	$ 395,035	$ 311,387
Charges to costs and expenses (income)	741,273	698,983	1,127,216
Acquisitions of business		506
Write-off of uncollectible accounts	(667,124)	(769,876)	(1,043,568)
Balance at end of period	398,797	324,648	395,035
Valuation Allowance for Deferred Tax Assets
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	52,764	46,841	44,511
Charges to costs and expenses (income)	(197)	5,923	2,330
Balance at end of period	$ 52,567	$ 52,764	$ 46,841