Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income and Other Expenses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	May 30, 2017
Accumulated other comprehensive items, net
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal			$ 0	$ 38,869
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	$ (74,082)	$ (161,239)	(103,989)	(212,573)
Other comprehensive loss:
Foreign currency translation adjustments	(135,756)	7,649	(105,664)	58,983
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	2,388	0	2,203	0
Total Other comprehensive (loss) income	(133,368)	7,649	(103,461)	58,983
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(207,450)	(153,590)	(207,450)	(153,590)
Total loss on foreign currency transactions	(18,624)	20,199	3,161	16,035
Other, net	(432)	(39,565)	(2,066)	(41,765)
Other (Income) Expense, Net	(19,056)	(19,366)	1,095	(25,730)
Russia and Ukraine Divestment \| Disposal Group, Not Discontinued Operations
Accumulated other comprehensive items, net
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		38,869		38,869
Disposal group, cumulative translation adjustment		29,100		29,100	$ 29,100
Foreign currency translation adjustments
Accumulated other comprehensive items, net
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(73,897)	(161,239)	(103,989)	(212,573)
Other comprehensive loss:
Foreign currency translation adjustments	(135,756)	7,649	(105,664)	58,983
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	0		0
Total Other comprehensive (loss) income	(135,756)	7,649	(105,664)	58,983
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(209,653)	$ (153,590)	(209,653)	$ (153,590)
Market value adjustments for securities
Accumulated other comprehensive items, net
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(185)		0
Other comprehensive loss:
Foreign currency translation adjustments	0		0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	2,388		2,203
Total Other comprehensive (loss) income	2,388		2,203
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	$ 2,203		$ 2,203

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