Debt Debt - Outstanding Debt (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($)
Excluding Impact [Member] | Variable Rate Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Carrying Value	$ 3,023,723
Debt, Percentage Interest Rate Remaining Term	3 years 3 months 18 days
Excluding Impact [Member] | Fixed Rate Debt [Member]
Debt Instrument [Line Items]
Debt, Percentage Interest Rate Remaining Term	3 years 3 months 18 days
Including Impact [Member]
Debt Instrument [Line Items]
Debt Instrument, Carrying Value	$ 6,613,118
Debt, Weighted Average Interest Rate	3.59%
Including Impact [Member] | Variable Rate Debt [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	1.78%
Including Impact [Member] | Fixed Rate Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Carrying Value	$ 3,589,395
Debt, Weighted Average Interest Rate	4.20%
Including Impact [Member] | Hedged Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Carrying Value	$ 1,822,973
Designated as Hedging Instrument [Member] | Including Impact [Member] | Fixed and Hedged Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Carrying Value	$ 5,412,368
Debt, Weighted Average Interest Rate	3.99%
Designated as Hedging Instrument [Member] | Including Impact [Member] | Hedged Debt [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	3.58%
Not Designated as Hedging Instrument [Member] | Including Impact [Member] | Unhedged Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Carrying Value	$ 1,200,750