Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		$ 3,420		$ 3,889		$ 6,241
Charged to Expense		3,586		3,917		954
Charged to Other Accounts		457	[1]	9	[1]	0
Deductions	[2]	3,829		4,395		3,306
Balance at End of Period		3,634		3,420		3,889
Allowance for returns
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		1,225		1,994		1,438
Charged to Expense		0		0		0
Charged to Other Accounts	[3]	1,561		4,890		2,088
Deductions	[4]	1,890		5,659		1,532
Balance at End of Period		896		1,225		1,994
Valuation allowance for deferred tax assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of Period		76,789		14,156		16,673
Charged to Expense		0		0		0
Charged to Other Accounts	[5]	8,611		62,633		(2,517)
Deductions		0		0		0
Balance at End of Period		$ 85,400		$ 76,789		$ 14,156

[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.