Financial Statement Presentation Cash, Cash Equivalents, and Restricted Cash (Tables)

6 Months Ended

Jun. 30, 2018

Cash and Cash Equivalents [Abstract]

Schedule of Cash and Cash Equivalents [Table Text Block]

Cash, Cash Equivalents, and Restricted Cash— The following table provides a summary of cash, cash equivalents, and restricted cash amounts reported on the Condensed Consolidated Balance Sheet that reconcile to the total of such amounts as shown on the Condensed Consolidated Statements of Cash Flows (in millions):

	June 30, 2018		December 31, 2017
Cash and cash equivalents	$	1,140	$	949
Restricted cash	379		274
Debt service reserves and other deposits	623		565
Cash, Cash Equivalents, and Restricted Cash	$	2,142	$	1,788