Revenue Recognition Revenue Recognition (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Allowance for Doubtful Accounts Receivable	$ 42,235		$ 52,924
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 27,179	$ 67,410
Contract With Customer Performance Obligation Not Substantially Completed		$ 24,000