Accounts Receivable and Allowance for Doubtful Accounts - Summary of Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Receivables [Abstract]
Balance at December 31, 2015	$ 16,877
Provision for doubtful accounts	5,483	$ 3,382
Accounts written off, net of recoveries	(3,896)
Balance at March 31, 2016	$ 18,464