Financing Narrative (Details) - USD ($) $ in Millions |
Jun. 15, 2016 |
Jun. 30, 2017 |
Dec. 31, 2016 |
Jun. 16, 2016 |
|---|---|---|---|---|
| Debt Instrument [Line Items] | ||||
| Debt discounts, premiums and issuance costs | $ 19.0 | $ 20.1 | ||
| Revolving Credit Facility [Member] | ||||
| Debt Instrument [Line Items] | ||||
| Debt Instrument, Term | 5 years | |||
| Line of Credit Facility, Current Borrowing Capacity | $ 1,500.0 | |||
| Senior Notes [Member] | ||||
| Debt Instrument [Line Items] | ||||
| Debt Instrument, Face Amount | $ 2,500.0 |