Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 674	$ 468
Adjustments to reconcile net income to net cash provided by operating activities from continuing operations:
Depreciation and other amortization	190	141
Amortization of acquisition-related intangible assets	80	78
Share-based compensation	36	33
Deferred income taxes	80	0
Gain on sale of businesses	(229)	(10)
Income from investments in unconsolidated affiliates	(7)	(26)
Dividends from unconsolidated affiliates	1	31
Non-cash impairment charges	1	10
Other operating activities	0	(1)
Changes in assets and liabilities, net of effects from acquisitions and dispositions:
Trade accounts receivable	(11)	59
Prepaid expenses and other assets	(64)	(13)
Contract costs	(76)	(12)
Accounts payable and other liabilities	17	(40)
Contract liabilities	(79)	(27)
Net cash provided by operating activities from continuing operations	613	691
Cash flows from investing activities:
Capital expenditures, including capitalization of software costs	(169)	(136)
Proceeds from sale of businesses	419	19
Payments for acquisition of business, net of cash acquired	0	(78)
Purchases of investments	(2)	0
Other investing activities	(12)	1
Net cash provided by (used in) investing activities from continuing operations	236	(194)
Cash flows from financing activities:
Debt proceeds	1,161	1,173
Debt repayments	(1,257)	(1,005)
Proceeds from issuance of treasury stock	44	47
Purchases of treasury stock, including employee shares withheld for tax obligations	(824)	(713)
Other financing activities	7	0
Net cash used in financing activities from continuing operations	(869)	(498)
Net change in cash and cash equivalents from continuing operations	(20)	(1)
Net change in cash and cash equivalents from discontinued operations	43	0
Cash and cash equivalents, beginning balance	325	300
Cash and cash equivalents, ending balance	348	299
Discontinued operations cash flow information:
Net cash used in operating activities	(7)	0
Net cash provided by investing activities	50	0
Net change in cash and cash equivalents from discontinued operations	$ 43	$ 0