Derivative Instruments (Narrative) (Details) - USD ($) shares in Thousands, $ in Millions |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
May 22, 2018 |
Dec. 31, 2017 |
|
| Derivative [Line Items] | ||||||
| Derivative assets | $ 2,221.3 | $ 2,221.3 | $ 2,127.7 | |||
| Cross-currency and interest rate derivative contracts | ||||||
| Derivative [Line Items] | ||||||
| Gain (loss) in changes in the credit risk valuation adjustments associated with our cross-currency and interest rate derivative contracts | (65.6) | $ 59.6 | (27.9) | $ 109.0 | ||
| Derivative assets | 1,715.7 | 1,715.7 | $ 1,548.9 | |||
| Counterparty Credit Risk | ||||||
| Derivative [Line Items] | ||||||
| Derivative assets | $ 456.1 | $ 456.1 | ||||
| Sumitomo Share Loan | ||||||
| Derivative [Line Items] | ||||||
| Aggregate market value of borrowed shares | $ 159.3 | |||||
| Ordinary shares | Lionsgate Loan | ||||||
| Derivative [Line Items] | ||||||
| Number of common stock shares owned (in shares) | 1,250 | 1,250 | ||||
| Nonvoting Common Stock | Lionsgate Loan | ||||||
| Derivative [Line Items] | ||||||
| Number of common stock shares owned (in shares) | 1,250 | 1,250 | ||||