Long-Term Debt and Credit Facilities - Settlement Lines of Credit (Details) € in Millions, zł in Millions, Kč in Millions, $ in Millions							1 Months Ended
	Jan. 31, 2019	Sep. 06, 2018 CZK (Kč)	Dec. 19, 2017 USD ($)	Dec. 01, 2017 USD ($)	Jun. 10, 2016 CZK (Kč)	Feb. 26, 2016 CZK (Kč)	Aug. 31, 2015 PLN (zł)	Dec. 31, 2018 USD ($)	Nov. 12, 2018 EUR (€)	May 29, 2018 USD ($)	Dec. 31, 2017 USD ($)
Credit Facility | Raiffeisen Bank Polska S.A
Long-term debt
Maximum borrowing capacity | Kč						Kč 400.0
Loan amounts drawn under the facility								$ 14.9			$ 5.2
Credit Facility | Deutsche Bank A.G.
Long-term debt
Maximum borrowing capacity				$ 35.0
Effective interest rate (as a percent)								7.00%
Borrowing capacity under the credit facility expressed as a percentage of eligible settlement receivables due				90.00%
Loan amounts drawn under the facility								$ 17.8			12.6
Credit Facility | Wells Fargo Bank N.A.
Long-term debt
Maximum borrowing capacity			$ 10.0							$ 15.0
Effective interest rate (as a percent)								6.50%
Loan amounts drawn under the facility								$ 0.0			9.9
Credit Facility | Banco Santander, S.A
Long-term debt
Maximum borrowing capacity | €									€ 10.0
Loan amounts drawn under the facility								$ 0.0
Credit Facility | CZK | Raiffeisen Bank Polska S.A
Long-term debt
Effective interest rate (as a percent)								2.55%
Credit Facility | Prague Interbank Offered Rate | CZK | Raiffeisen Bank Polska S.A
Long-term debt
Basis spread on variable rate (as a percent)	1.00%					0.80%
Credit Facility | EONIA | EUR | Raiffeisen Bank Polska S.A
Long-term debt
Basis spread on variable rate (as a percent)						0.80%
Credit Facility | LIBOR | GBP | Raiffeisen Bank Polska S.A
Long-term debt
Basis spread on variable rate (as a percent)						0.80%
Credit Facility | LIBOR | USD | Raiffeisen Bank Polska S.A
Long-term debt
Basis spread on variable rate (as a percent)						0.80%
Credit Facility | Prime rate | Deutsche Bank A.G.
Long-term debt
Basis spread on variable rate (as a percent)				1.50%
Credit Facility | Prime rate | Wells Fargo Bank N.A.
Long-term debt
Basis spread on variable rate (as a percent)			1.00%
Overdraft facility | Bank BGZ BNP Paribas S.A
Long-term debt
Maximum borrowing capacity | zł							zł 20.0
Threshold amount for determining basis spread on variable rate | zł							zł 10.0
Loan amounts drawn under the facility								$ 2.9			0.8
Overdraft facility | PKO Bank
Long-term debt
Maximum borrowing capacity | Kč					Kč 239.1
Effective interest rate (as a percent)								3.14%
Loan amounts drawn under the facility								$ 6.1			$ 1.8
Overdraft facility | PKO Bank Polski
Long-term debt
Maximum borrowing capacity | Kč		Kč 100.0
Effective interest rate (as a percent)								3.38%
Loan amounts drawn under the facility								$ 0.1
Overdraft facility | Banco Santander, S.A
Long-term debt
Interest rate (as a percent)									3.00%
Overdraft facility | Drawdowns below 10 million | Bank BGZ BNP Paribas S.A
Long-term debt
Effective interest rate (as a percent)								2.34%
Overdraft facility | Drawdowns above 10 million | Bank BGZ BNP Paribas S.A
Long-term debt
Effective interest rate (as a percent)								2.89%
Overdraft facility | WIBOR | Drawdowns below 10 million | Bank BGZ BNP Paribas S.A
Long-term debt
Basis spread on variable rate (as a percent)							0.70%
Overdraft facility | WIBOR | Drawdowns above 10 million | Bank BGZ BNP Paribas S.A
Long-term debt
Basis spread on variable rate (as a percent)							1.25%
Overdraft facility | Prague Interbank Offered Rate | PKO Bank
Long-term debt
Basis spread on variable rate (as a percent)					1.25%
Overdraft facility | Prague Interbank Offered Rate | PKO Bank Polski
Long-term debt
Basis spread on variable rate (as a percent)		1.50%