Allowance for Doubtful Accounts (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Allowance For Doubtful Accounts Receivable Rollforward
Balance at beginning of period			$ 6,062,000
Provisions recognized as reduction in revenues	$ 2,598,924	$ 2,177,522	4,520,909	$ 2,598,546
Write-offs, net of recoveries			(5,532,909)
Balance at end of period	$ 5,050,000		$ 5,050,000