Derivative Financial Instruments - Hedging of Debt Portfolio (Details)	Dec. 31, 2016 USD ($)
Interest rate swap February 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Value	$ 500,000,000
Fixed Coupon Rate on Hedged Debt (as a percent)	5.25%
Interest rate swap, April 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Value	$ 500,000,000
Fixed Coupon Rate on Hedged Debt (as a percent)	1.90%
Interest rate swap October 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Value	$ 750,000,000
Fixed Coupon Rate on Hedged Debt (as a percent)	2.60%
Interest rate swap July 2021
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Value	$ 500,000,000
Fixed Coupon Rate on Hedged Debt (as a percent)	2.50%