Business Segment Information (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) segment contract	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Core business segments, number | segment	3
Non-core business segments, number | segment	2
Number of contracts (more than) | contract	1,000
Additional revenue and gross profit recognized | $			$ 35
MMM Joint Venture
Segment Reporting Information [Line Items]
Equity in earnings (losses) of unconsolidated affiliates | $	$ (13)	$ (3)