Income Taxes - Tax Loss Carryforwards and Related Tax Assets (Details) $ in Millions	Dec. 31, 2019 USD ($)
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	$ 8,417.0
Related tax asset	1,389.4
U.K.
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	1,358.8
Related tax asset	230.1
U.K. | Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	4,924.2
Related tax asset	837.1
Barbados
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	1,088.0
Related tax asset	28.6
Jamaica
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	448.7
Related tax asset	148.7
Curacao
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	207.1
Related tax asset	45.6
U.S.
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	117.2
Related tax asset	29.3
Puerto Rico
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	31.3
Related tax asset	10.2
Chile
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	22.6
Related tax asset	6.1
Other
Operating Loss Carryforwards [Line Items]
Tax loss carryforward	219.1
Related tax asset	$ 53.7