Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance for Deferred Tax Assets [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period		$ 336,146	$ 331,589	$ 292,388
Charged to Costs and Expenses	[1]	14,675	6,056	38,761
Charged to Other Accounts		(15,830)	(1,499)	440
Balance at End of Period		334,991	336,146	331,589
Allowance for Doubtful and Disputed Accounts [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period		14,325	30,391	30,404
Charged to Costs and Expenses			89	3,698
Write-offs		(26)	(16,119)	(3,689)
Recoveries			(36)	(22)
Balance at End of Period		$ 14,299	$ 14,325	$ 30,391

[1] (1)Net of reductions and other adjustments, all of which are charged to costs and expenses.