Allowance for Sales Returns - Summary of Allowance for Sales Returns (Details) - 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 period	$ 9,806	$ 8,980
Balance, end of period	13,829	9,806	$ 8,980
Allowance for sales returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of period	4,155	6,266	7,748
Reserve accrual	17,108	13,042	20,146
Recoveries and deductions, net	(14,995)	(15,153)	(21,628)
Balance, end of period	$ 6,268	$ 4,155	$ 6,266