Derivatives and Hedging Activities Derivatives and Hedging Activities - Schedule of Interest Rate Swaps Outstanding (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Notional Amount	$ 14,488,077	$ 14,609,961
Interest Rate Swaps
Derivative [Line Items]
Notional Amount	$ 14,000,000	$ 12,370,000
Weighted Average Fixed Pay Rate	1.47%	2.46%
Weighted Average Receive Rate	1.79%	2.55%
Weighted Average Years to Maturity	5 years 2 months 12 days	3 years 8 months 12 days
Interest Rate Swaps | 1-Month LIBOR
Derivative [Line Items]
Notional Amount	$ 10,700,000	$ 6,700,000
Interest Rate Swaps | 3-Month LIBOR
Derivative [Line Items]
Notional Amount	3,300,000	5,700,000
2020 | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	$ 1,900,000	$ 1,500,000
Weighted Average Fixed Pay Rate	1.67%	2.70%
Weighted Average Receive Rate	1.84%	2.47%
Weighted Average Years to Maturity	18 days	10 months 24 days
2021 | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	$ 2,500,000	$ 1,500,000
Weighted Average Fixed Pay Rate	1.40%	2.78%
Weighted Average Receive Rate	1.77%	2.51%
Weighted Average Years to Maturity	1 year 3 months 18 days	1 year 8 months 12 days
2022 | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	$ 800,000	$ 2,300,000
Weighted Average Fixed Pay Rate	1.53%	2.51%
Weighted Average Receive Rate	1.91%	2.58%
Weighted Average Years to Maturity	2 years 10 months 24 days	2 years 6 months
2023 | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	$ 2,400,000	$ 2,550,000
Weighted Average Fixed Pay Rate	1.44%	2.13%
Weighted Average Receive Rate	1.72%	2.65%
Weighted Average Years to Maturity	3 years 10 months 24 days	3 years 4 months 24 days
2024 | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	$ 900,000	$ 1,600,000
Weighted Average Fixed Pay Rate	1.49%	2.39%
Weighted Average Receive Rate	1.76%	2.47%
Weighted Average Years to Maturity	4 years 9 months 18 days	4 years 8 months 12 days
Thereafter | Interest Rate Swaps
Derivative [Line Items]
Notional Amount	$ 5,500,000	$ 2,920,000
Weighted Average Fixed Pay Rate	1.44%	2.47%
Weighted Average Receive Rate	1.78%	2.55%
Weighted Average Years to Maturity	9 years 6 months	6 years 9 months 18 days