CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Mar. 31, 2017
Statement of Cash Flows [Abstract]
Cash and cash equivalents	$ 177	$ 183
Restricted cash included in Prepaid expenses and other current assets	6	0
Total cash, cash equivalents, and restricted cash at end of the period	$ 183	$ 183