Schedule II - Valuation And Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation And Qualifying Accounts [Abstract]
Beginning Balance	$ 50,406	$ 31,386	$ 28,655
Charged to Expenses/Against Revenue	8,788	21,156	7,384
Deferred Revenue Reclassification	(6,029)	5,512	1,482
Write-Offs, Net of Recoveries	(8,221)	(7,648)	(6,135)
Ending Balance	$ 44,944	$ 50,406	$ 31,386