SCHEDULE II. VALUATION AND QUALIFYING ACCOUNTS Transactions in the Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of year	$ 41,051	$ 39,292	$ 34,560
Provision	11,538	15,092	15,587
Write-offs	(9,134)	(13,333)	(10,855)
Balance, end of year	$ 43,455	$ 41,051	$ 39,292