Income Taxes - Reconciliation of Effective Tax Rate (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
U.S. federal statutory tax rate	21.00%	21.00%	21.00%	21.00%
State income taxes, net of federal benefit	1.70%	1.50%	1.20%	(0.20%)
Non-U.S. income taxed at different rates	0.20%	3.90%	0.80%	0.60%
Reduction in tax benefit related to stock-based awards	(0.60%)	(4.90%)	(1.40%)	(1.70%)
Non-deductible expenses	(0.70%)	(8.60%)	(0.40%)	(9.20%)
Research and development credit (expense)	0.20%	(3.50%)	0.50%	0.30%
Increase in valuation allowance	(18.80%)	(3.40%)	(18.20%)	(33.60%)
Other	(1.40%)	0.00%	(0.70%)	0.00%
Effective income tax rate	1.60%	6.00%	2.80%	(22.80%)

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.

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Percentage of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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