Segment Information - EBITDA Reconciliation to Net Earnings (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Adjusted EBITDA
Adjusted EBITDA	$ 71	$ 50
Amortization of intangibles	(2)	(2)
Depreciation	(12)	(11)
Restructuring costs	0	(2)
Interest expense	(9)	(15)
Transaction costs related to an anticipated offering of securities	(4)	0
Acquisition and divestiture related expenses
Foreign exchange	0	(5)
COVID-19 response costs	(3)	0
Non-service pension expense	0	(2)
Other one-time non-operational events		0
Income tax (provision) benefit	(12)	(3)
Net earnings	29	10
AST
Adjusted EBITDA
Depreciation	(5)	(5)
NC&C
Adjusted EBITDA
Depreciation	(3)	(3)
IMS
Adjusted EBITDA
Depreciation	(4)	(3)
Operating Segments | AST
Adjusted EBITDA
Adjusted EBITDA	28	17
Operating Segments | NC&C
Adjusted EBITDA
Adjusted EBITDA	26	19
Operating Segments | IMS
Adjusted EBITDA
Adjusted EBITDA	18	15
Corporate & Eliminations
Adjusted EBITDA
Adjusted EBITDA	$ (1)	$ (1)