Accounts Receivable - Activity in Accounts Receivable Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning balance	$ 9,023	$ 3,703	$ 3,807
Charges to income from operations	37,870	32,293	17,900
Collections from cash basis customers	(39,529)	(26,973)	(18,004)
Ending balance	$ 7,364	$ 9,023	$ 3,703