Commitments and Contingencies (Details) $ in Thousands, € in Millions	1 Months Ended						3 Months Ended	9 Months Ended
	Jan. 31, 2014 USD ($)	Jan. 31, 2014 EUR (€)	Dec. 31, 2013 USD ($)	Dec. 31, 2013 EUR (€)	Nov. 30, 2013 USD ($)	Nov. 30, 2013 EUR (€)	Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 EUR (€)	Feb. 28, 2014 EUR (€)
Other Commitments [Line Items]
Leasehold improvements, net							$ 0
Non-cash investing activities, fair value of assets acquired								$ 44,600
Non-cash financing activities, notes issued								42,900
Wrongful Termination Lawsuit - Productions Graphics [Member]
Other Commitments [Line Items]
Loss contingency, damages sought			$ 1,000	€ 0.7	$ 1,000	€ 0.7
Loss contingency, damages value, contingent consideration									$ 9,400	€ 7.1	€ 7.1
Loss contingency, damages value, fixed consideration									8,000	5.8
Loss contingency, damages maximum, contingent consideration									$ 37,600	€ 34.5
Employment Arbitration Claim [Member]
Other Commitments [Line Items]
Loss contingency, damages sought	$ 700	€ 0.6
Portland
Other Commitments [Line Items]
Fair value of buildings leased							9,000	9,000
Financing obligation, build-to-suit leases							8,900	8,900
Rent expense							300	300
Prague
Other Commitments [Line Items]
Fair value of buildings leased							35,600	35,600
Financing obligation, build-to-suit leases							33,900	33,900
Rent expense								300
Accounts payable							$ 1,700	$ 1,700