Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		$ 1,400
Balance at End of Period		2,000	$ 1,400
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		6,281	3,791	$ 3,292
Charged to Expense		922	5,664	2,861
Charged to Other Accounts		0	0	76	[1]
Deductions	[2]	3,314	3,174	2,438
Balance at End of Period		3,889	6,281	3,791
Allowance for returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		1,438	2,185	2,062
Charged to Expense		0	0	0
Charged to Other Accounts	[3]	2,088	3,276	5,049
Deductions	[4]	1,532	4,023	4,926
Balance at End of Period		1,994	1,438	2,185
Valuation allowance for deferred tax assets
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		16,673	15,167	26,465
Charged to Expense		0	0	0
Charged to Other Accounts	[5]	(2,517)	1,506	(11,298)
Deductions		0	0	0
Balance at End of Period		$ 14,156	$ 16,673	$ 15,167

[1] Adjustments from acquisitions.

[2] Uncollectible accounts written off, net of recoveries.

[3] Charged against revenues.

[4] Credits issued for returns.

[5] Related to deferred tax assets on foreign tax credits, net operating loss carryforwards, and depreciation.