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Face amount or stated value per share of common stock.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount before tax of foreign currency transaction realized gain (loss) recognized in the income statement.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Significant Accounting Policies - Additional Information (Details) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2016 investee	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2016	Mar. 13, 2015	Mar. 10, 2015
JV
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Ownership percentage	10.00%	50.00%
VIE
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Ownership percentage	10.00%	50.00%
Number of other parties \| investee	9
Minimum
Goodwill and intangible assets
Amortization period		1 year
Foreign currency translation and foreign currency forward contracts
Fixed assets, useful life		3 years
Maximum
Goodwill and intangible assets
Amortization period		7 years
Foreign currency translation and foreign currency forward contracts
Fixed assets, useful life		7 years
Investment Income and Other, Net
Foreign currency translation and foreign currency forward contracts
Gain (loss) on foreign currency transactions \| $		$ 0.1	$ (0.7)	$ (2.0)
Senior Secured Notes \| 6.875% Senior Secured Notes
Repurchases of debt
Interest rate (percent)		6.875%	6.875%		6.875%	6.875%	6.875%
Common Class A
Repurchases of common stock
Common stock, par value (in dollars per share) \| $ / shares		$ 0.01
Software
Goodwill and intangible assets
Amortization period		3 years