Revenue Recognition and Contractual Adjustments - Adjustment of Transactions Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue Recognition [Abstract]
Gross service revenues	$ 114,902	$ 57,192	$ 376,857	$ 167,525
Total contractual adjustments and discounts	(54,141)	(32,066)	(193,264)	(95,002)
Total Revenue, net	$ 60,761	$ 25,126	$ 183,593	$ 72,523