Stockholders' Equity 1 (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016
Cash dividends
Declaration date	Nov. 09, 2017	Aug. 09, 2017	May 09, 2017	Nov. 02, 2016	Aug. 03, 2016	May 04, 2016
Dividend per share (in dollars per share)	$ 0.255	$ 0.255	$ 0.255	$ 0.255	$ 0.255	$ 0.255
Record date	Nov. 30, 2017	Aug. 24, 2017	May 25, 2017	Nov. 17, 2016	Aug. 25, 2016	May 26, 2016
Total amount	$ 106	$ 108	$ 107	$ 107	$ 107	$ 107
Payment date	Dec. 12, 2017	Sep. 12, 2017	Jun. 13, 2017	Dec. 06, 2016	Sep. 13, 2016	Jun. 14, 2016

Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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