Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation and Qualifying Accounts Disclosure [Line Items]
Provision For Doubtful Accounts	$ 14,053	$ 16,369	$ 16,461
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance, Beginning Balance	14,300	14,200	21,000
Provision For Doubtful Accounts	14,100	16,400	16,400
Write-Offs	(11,900)	(16,300)	(23,200)
Valuation Allowances and Reserves, Balance, Ending Balance	16,500	14,300	14,200
Allowance for Doubtful Accounts - Discontinued Operations [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Provision For Doubtful Accounts		100	600
Estimated Revenue Adjustments [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance, Beginning Balance	3,100	3,900	6,400
Provision for Estimated Revenue Adjustments	6,100	5,100	9,400
Write-Offs	(5,200)	(5,900)	(11,900)
Valuation Allowances and Reserves, Balance, Ending Balance	$ 4,000	3,100	3,900
Estimated Revenue Adjustments, Discontinued Operations [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Provision for Estimated Revenue Adjustments		$ 100	$ 400