Shareholders' Deficit - Schedule of Changes in Shareholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	$ (590,472)	$ (494,450)	$ (498,283)	$ (62,077)	$ (7,093)	$ 484,880	$ (498,283)	$ 484,880
Effect of adopting accounting principle in period of adoption									$ (4,646)		$ 3,076
Shareholders' equity, adjusted beginning balance									(502,929)		487,956
Net loss	(79,415)	(106,005)	(18,573)	(173,205)	(60,867)	(505,489)	(203,993)	(739,561)
Other comprehensive income (loss)	(2,515)	4,395	4,730	4,735	(5,971)	(5,797)	6,610	(7,033)
Compensation related to share-based awards	11,576	12,600	24,733	13,736	12,096	17,890
Exercise of options			4	473
Tax withholding for restricted shares	(650)	(7,013)	(2,414)	(3,206)	(234)	(1,642)
Other	(1)	1	(1)	85	(8)	(11)
Shareholders' equity, ending balance	(661,477)	(590,472)	(494,450)	(219,459)	(62,077)	(7,093)	(661,477)	(219,459)
Accumulated deficit	(9,333,571)						(9,333,571)			$ (9,124,932)
Euro Deferred Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	45	45	46	47	49	48	46	48
Shareholders' equity, adjusted beginning balance									46		48
Other	(1)		(1)	(1)	(2)	1
Shareholders' equity, ending balance	44	45	45	46	47	49	44	46
Ordinary Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	23	22	22	22	22	22	22	22
Shareholders' equity, adjusted beginning balance									22		22
Other	0	1
Shareholders' equity, ending balance	23	23	22	22	22	22	23	22
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	8,883,720	8,878,133	8,855,810	8,819,262	8,807,406	8,791,170	8,855,810	8,791,170
Shareholders' equity, adjusted beginning balance									8,855,810		8,791,170
Compensation related to share-based awards	11,576	12,600	24,733	13,736	12,096	17,890	48,900	43,700
Exercise of options			4	473
Tax withholding for restricted shares	(650)	(7,013)	(2,414)	(3,206)	(234)	(1,642)
Other	0	0		86	(6)	(12)
Shareholders' equity, ending balance	8,894,646	8,883,720	8,878,133	8,830,351	8,819,262	8,807,406	8,894,646	8,830,351
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	(9,254,156)	(9,148,151)	(9,124,932)	(8,659,819)	(8,598,952)	(8,096,539)	(9,124,932)	(8,096,539)
Effect of adopting accounting principle in period of adoption									(4,646)		3,076
Shareholders' equity, adjusted beginning balance									(9,129,578)		(8,093,463)
Net loss	(79,415)	(106,005)	(18,573)	(173,205)	(60,867)	(505,489)
Shareholders' equity, ending balance	(9,333,571)	(9,254,156)	(9,148,151)	(8,833,024)	(8,659,819)	(8,598,952)	(9,333,571)	(8,833,024)
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	(220,104)	(224,499)	(229,229)	(221,589)	(215,618)	(209,821)	(229,229)	(209,821)
Shareholders' equity, adjusted beginning balance									$ (229,229)		(209,821)
Other comprehensive income (loss)	(2,515)	4,395	4,730	4,735	(5,971)	(5,797)
Shareholders' equity, ending balance	$ (222,619)	$ (220,104)	$ (224,499)	$ (216,854)	$ (221,589)	$ (215,618)	$ (222,619)	$ (216,854)
Effect of adoption of ASC 606 | ASC 606
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated deficit											$ 3,100