Investments Investments (Leveraged and Direct Financing Leases - Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Investments, All Other Investments [Abstract]
Leveraged Leases, net of allowance for credit losses	$ 901
Direct Financing Leases, net of allowance for credit losses	1,100
Leveraged and Direct Financing Leases, Allowance for credit loss	$ 56
Leveraged Leases, Net Investment in Leveraged Leases Disclosure, Investment in Leveraged Leases, Net		$ 1,100
Direct Financing Lease, Net Investment in Lease		$ 1,200
Loans and Leases Receivable, Other Information	The payment periods for leveraged leases generally range from one to 12 years but in certain circumstances can be over 12 years, while the payment periods for direct financing leases generally range from one to 25 years but in certain circumstances can be over 25 years.