Income Taxes (Net Operating and Capital Loss Carryforwards) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Net deferred tax assets
Total net deferred tax assets	$ 40.4	$ 27.5
Alternative minimum tax credit carryforwards, not subject to expiration	0.7
United States
Net deferred tax assets
Operating loss carryforwards	3.7
Stock Compensation Plan [Member] | United States
Net deferred tax assets
Operating loss carryforwards	6.8
Operating and Capital Loss Carryforward
Net deferred tax assets
Operating loss carryforwards	577.5
Gross deferred tax asset	126.3
Valuation allowance	(123.1)
Total net deferred tax assets	3.2
Operating and Capital Loss Carryforward | United States
Net deferred tax assets
Operating loss carryforwards	424.7
Gross deferred tax asset	89.7
Valuation allowance	(87.3)
Total net deferred tax assets	2.4
Operating and Capital Loss Carryforward | Luxembourg
Net deferred tax assets
Operating loss carryforwards	76.8
Gross deferred tax asset	20.0
Valuation allowance	(20.0)
Total net deferred tax assets	0.0
Operating and Capital Loss Carryforward | United Kingdom
Net deferred tax assets
Operating loss carryforwards	14.9
Gross deferred tax asset	2.6
Valuation allowance	(1.8)
Total net deferred tax assets	0.8
Operating and Capital Loss Carryforward | Israel
Net deferred tax assets
Operating loss carryforwards	61.1
Gross deferred tax asset	14.0
Valuation allowance	(14.0)
Total net deferred tax assets	0.0
2019-2023 | Operating and Capital Loss Carryforward
Net deferred tax assets
Operating loss carryforwards	0.4
2019-2023 | Operating and Capital Loss Carryforward | United States
Net deferred tax assets
Operating loss carryforwards	0.4
2019-2023 | Operating and Capital Loss Carryforward | Luxembourg
Net deferred tax assets
Operating loss carryforwards	0.0
2019-2023 | Operating and Capital Loss Carryforward | United Kingdom
Net deferred tax assets
Operating loss carryforwards	0.0
2019-2023 | Operating and Capital Loss Carryforward | Israel
Net deferred tax assets
Operating loss carryforwards	0.0
2024-2028 | Operating and Capital Loss Carryforward
Net deferred tax assets
Operating loss carryforwards	0.0
2024-2028 | Operating and Capital Loss Carryforward | United States
Net deferred tax assets
Operating loss carryforwards	0.0
2024-2028 | Operating and Capital Loss Carryforward | Luxembourg
Net deferred tax assets
Operating loss carryforwards	0.0
2024-2028 | Operating and Capital Loss Carryforward | United Kingdom
Net deferred tax assets
Operating loss carryforwards	0.0
2024-2028 | Operating and Capital Loss Carryforward | Israel
Net deferred tax assets
Operating loss carryforwards	0.0
2029-2038 | Operating and Capital Loss Carryforward
Net deferred tax assets
Operating loss carryforwards	389.8
2029-2038 | Operating and Capital Loss Carryforward | United States
Net deferred tax assets
Operating loss carryforwards	342.8
2029-2038 | Operating and Capital Loss Carryforward | Luxembourg
Net deferred tax assets
Operating loss carryforwards	47.0
2029-2038 | Operating and Capital Loss Carryforward | United Kingdom
Net deferred tax assets
Operating loss carryforwards	0.0
2029-2038 | Operating and Capital Loss Carryforward | Israel
Net deferred tax assets
Operating loss carryforwards	0.0
No expiration date | Operating and Capital Loss Carryforward
Net deferred tax assets
Operating loss carryforwards	187.3
No expiration date | Operating and Capital Loss Carryforward | United States
Net deferred tax assets
Operating loss carryforwards	81.5
No expiration date | Operating and Capital Loss Carryforward | Luxembourg
Net deferred tax assets
Operating loss carryforwards	29.8
No expiration date | Operating and Capital Loss Carryforward | United Kingdom
Net deferred tax assets
Operating loss carryforwards	14.9
No expiration date | Operating and Capital Loss Carryforward | Israel
Net deferred tax assets
Operating loss carryforwards	$ 61.1