Income Taxes (Details 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Analysis of effective income tax rate for continuing operations
Notional U.S. federal income tax expense at the statutory rate	$ 21,815	$ 9,831	$ 33,420	$ 30,492
U.S. state and local income tax, net	33	14	122	139
Non-deductible expenses in the U.S.	(104)	133	(298)	418
Other	(6)	(2)	(23)	(26)
Provision for income taxes	6,195	2,458	8,536	8,782
Bermuda
Analysis of effective income tax rate for continuing operations
Non-U.S. operations:			(10,632)	(16,687)
Ireland
Analysis of effective income tax rate for continuing operations
Non-U.S. operations:			(569)	2,155
Other
Analysis of effective income tax rate for continuing operations
Non-U.S. operations:			(4,377)	(2,835)
Singapore | Foreign Tax Authority
Analysis of effective income tax rate for continuing operations
Non-U.S. operations:	(1,518)	(823)	$ (9,107)	$ (4,874)
Other | Foreign Tax Authority
Analysis of effective income tax rate for continuing operations
Non-U.S. operations:	(1,450)	(752)
Ireland | Foreign Tax Authority
Analysis of effective income tax rate for continuing operations
Non-U.S. operations:	(315)	82
Bermuda | Foreign Tax Authority
Analysis of effective income tax rate for continuing operations
Non-U.S. operations:	$ (12,260)	$ (6,025)