Variable Interest Entities And Preferred Securities Of Subsidiaries (Activity Between Company And Entities) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Cash receipts (b)		$ 153	$ 133	$ 58
Two Thousand Seven Financing Entities [Member]
Variable Interest Entity [Line Items]
Revenue (a)	[1]	72	49	37
Expense (a)	[2]	67	48	37
Cash receipts (b)	[3]	48	28	15
Cash payments (c)	[4]	57	39	27
Entities [Member]
Variable Interest Entity [Line Items]
Revenue (a)	[5]	95	95	95
Expense (a)	[5]	128	128	128
Cash receipts (b)	[6]	95	95	77
Cash payments (c)	[7]	$ 128	$ 128	$ 98

[1] The revenue is included in Interest expense, net, in the accompanying consolidated statement of operations and includes approximately $19 million for the years ended December 31, 2018, 2017 and 2016, respectively, of accretion income for the amortization of the purchase accounting adjustment on the Financial assets of special purpose entities.

[2] The expense is included in Interest expense, net, in the accompanying consolidated statement of operations and includes approximately $7 million for the years ended December 31, 2018, 2017 and 2016, respectively, of accretion expense for the amortization of the purchase accounting adjustment on the Nonrecourse financial liabilities of special purpose entities.

[3] The cash receipts are interest received on the Financial assets of special purpose entities.

[4] The cash payments are interest paid on Nonrecourse financial liabilities of special purpose entities.

[5] The revenue and expense are included in Interest expense, net in the accompanying consolidated statement of operations.

[6] The cash receipts are interest received on the Financial assets of special purpose entities.

[7] The cash payments represent interest paid on Nonrecourse financial liabilities of special purpose entities.