Shareholders' Deficit (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	$ (737,817)	$ (866,544)	$ (494,450)	$ (498,283)	$ (866,544)	$ (498,283)
Net income (loss)	10,558	129,930	(106,005)	(18,573)	140,488	(124,578)
Other comprehensive income (loss)	5,624	(14,437)	4,395	4,730	(8,813)	9,125
Compensation related to share-based awards	9,222	17,645	12,600	24,733
Exercise of options			(7,013)	4
Tax withholding for restricted shares	(2,467)	(4,398)		(2,414)
Other	13	(13)	1	(1)
Shareholders' equity, ending balance	(714,867)	(737,817)	(590,472)	(494,450)	(714,867)	$ (590,472)	$ (498,283)
Accounting Standards Update [Extensible List]						us-gaap:AccountingStandardsUpdate201602Member	us-gaap:AccountingStandardsUpdate201602Member
Cumulative Effect, Period of Adoption, Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance				(4,646)		$ (4,646)
Shareholders' equity, ending balance							$ (4,646)
Cumulative Effect, Period of Adoption, Adjusted Balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance				(502,929)		(502,929)
Shareholders' equity, ending balance							(502,929)
Euro Deferred Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	44	45	45	46	45	46
Other		(1)		(1)
Shareholders' equity, ending balance	45	44	45	45	45	45	46
Euro Deferred Shares | Cumulative Effect, Period of Adoption, Adjusted Balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance				46		46
Shareholders' equity, ending balance							46
Ordinary Shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	23	23	22	22	23	22
Other			1
Shareholders' equity, ending balance	23	23	23	22	23	23	22
Ordinary Shares | Cumulative Effect, Period of Adoption, Adjusted Balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance				22		22
Shareholders' equity, ending balance							22
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	8,917,927	8,904,692	8,878,133	8,855,810	8,904,692	8,855,810
Compensation related to share-based awards	9,222	17,645	12,600	24,733	26,900	37,300
Exercise of options			(7,013)	4
Tax withholding for restricted shares	(2,467)	(4,398)		(2,414)
Other	12	(12)
Shareholders' equity, ending balance	8,924,694	8,917,927	8,883,720	8,878,133	8,924,694	8,883,720	8,855,810
Additional Paid-in Capital | Cumulative Effect, Period of Adoption, Adjusted Balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance				8,855,810		8,855,810
Shareholders' equity, ending balance							8,855,810
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	(9,422,284)	(9,552,214)	(9,148,151)	(9,124,932)	(9,552,214)	(9,124,932)
Net income (loss)	10,558	129,930	(106,005)	(18,573)
Shareholders' equity, ending balance	(9,411,726)	(9,422,284)	(9,254,156)	(9,148,151)	(9,411,726)	(9,254,156)	(9,124,932)
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance				(4,646)		(4,646)
Shareholders' equity, ending balance							(4,646)
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjusted Balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance				(9,129,578)		(9,129,578)
Shareholders' equity, ending balance							(9,129,578)
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	(233,527)	(219,090)	(224,499)	(229,229)	(219,090)	(229,229)
Other comprehensive income (loss)	5,624	(14,437)	4,395	4,730
Shareholders' equity, ending balance	$ (227,903)	$ (233,527)	$ (220,104)	(224,499)	$ (227,903)	(220,104)	(229,229)
Accumulated Other Comprehensive Loss | Cumulative Effect, Period of Adoption, Adjusted Balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance				$ (229,229)		$ (229,229)
Shareholders' equity, ending balance							$ (229,229)