Income Taxes (Benefit (Expense) of Income Tax) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Income Taxes [Line Items] | |||
| Current | $ (187.5) | $ (1,135.2) | $ (192.3) |
| Deferred | (65.5) | (438.1) | (46.6) |
| Total income tax expense | (253.0) | (1,573.3) | (238.9) |
| The Netherlands | |||
| Income Taxes [Line Items] | |||
| Current | 0.0 | 14.2 | (16.2) |
| Deferred | (275.3) | (519.4) | (118.2) |
| Total | (275.3) | (505.2) | (134.4) |
| Belgium | |||
| Income Taxes [Line Items] | |||
| Current | (134.7) | (153.9) | (203.6) |
| Deferred | 3.6 | 41.6 | 145.4 |
| Total | (131.1) | (112.3) | (58.2) |
| U.K. | |||
| Income Taxes [Line Items] | |||
| Current | (1.5) | (7.2) | (3.3) |
| Deferred | 118.8 | 32.2 | (64.7) |
| Total | 117.3 | 25.0 | (68.0) |
| U.S. | |||
| Income Taxes [Line Items] | |||
| Current | (4.1) | (957.5) | 47.2 |
| Deferred | 81.9 | 7.6 | (32.8) |
| Total | 77.8 | (949.9) | 14.4 |
| Switzerland | |||
| Income Taxes [Line Items] | |||
| Current | (27.8) | (16.6) | (2.0) |
| Deferred | (1.1) | 6.2 | 15.6 |
| Total | (28.9) | (10.4) | 13.6 |
| Other | |||
| Income Taxes [Line Items] | |||
| Current | (19.4) | (14.2) | (14.4) |
| Deferred | 6.6 | (6.3) | 8.1 |
| Total | $ (12.8) | $ (20.5) | $ (6.3) |