Financial Information for Guarantor Subsidiaries and Non-Guarantor Subsidiaries - Supplemental Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended		9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Financial Statements
Revenue	$ 855		$ 821				$ 2,537	$ 2,478
Cost of services, cost of product sales and cost of instant products(2)	317		301				945	914
Selling, general and administrative	175		170				535	515
Research and development	47		50				142	153
Depreciation, amortization and impairments	162		166				497	527
Restructuring and other	11		339				24	424
Operating (loss) income	143		(205)				394	(55)
Interest expense	(146)		(147)				(447)	(448)
Gain (Loss) on Extinguishment of Debt	0		0				(60)	(93)
Gain (loss) on remeasurement of debt	19		(4)				21	29
Other income (expense), net	(1)		4				19	14
Net (loss) income before equity in income of subsidiaries and income taxes	15		(352)				(73)	(553)
Equity in (loss) income of subsidiaries	0		0				0	0
Income tax benefit (expense)	3		0				(8)	(6)
Net income (loss)	18		(352)		$ (75)		(81)	(559)
Less: Net income attributable to noncontrolling interest	4						6
Net Income (Loss) Attributable to Parent	14	$ (24)	(352)	$ (202)	(77)	$ (6)	(87)	(559)
Other comprehensive loss	(35)	$ 51	(5)	$ 52	(51)	$ (83)		(37)
Foreign currency translation gain, net of tax	(38)		(8)				(22)	(46)
Derivative financial instruments unrealized gain (loss), net of tax	3		3				(13)	9
Other Comprehensive Income (Loss), Net of Tax	(35)						(35)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(17)		(357)				(116)	(596)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	4		0		$ 2		6	0
Comprehensive (loss) income attributable to SGC	(21)		(357)				(122)	(596)
Reportable Legal Entities | SGI (Issuer)
Condensed Financial Statements
Revenue	139		138				444	404
Cost of services, cost of product sales and cost of instant products(2)	93		90				288	263
Selling, general and administrative	9		12				29	32
Research and development	1		0				3	1
Depreciation, amortization and impairments	8		9				33	24
Restructuring and other	1		3				2	0
Operating (loss) income	27		24				89	84
Interest expense	(146)		(147)				(447)	(448)
Gain (Loss) on Extinguishment of Debt							(60)	(93)
Gain (loss) on remeasurement of debt	19		(4)				21	29
Other income (expense), net	129		130				392	399
Net (loss) income before equity in income of subsidiaries and income taxes	29		3				(5)	(29)
Equity in (loss) income of subsidiaries	9		4				18	22
Income tax benefit (expense)	(8)		(1)				1	7
Net income (loss)	30						14
Less: Net income attributable to noncontrolling interest	0						0
Net Income (Loss) Attributable to Parent	30		6				14	0
Other comprehensive loss			11					23
Other Comprehensive Income (Loss), Net of Tax	30						24
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	60						38
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	0						0
Comprehensive (loss) income attributable to SGC	60		17				38	23
Reportable Legal Entities | SGC (Parent)
Condensed Financial Statements
Revenue	0		0				0	0
Cost of services, cost of product sales and cost of instant products(2)	0		0				0	0
Selling, general and administrative	34		38				100	119
Research and development	0		0				0	0
Depreciation, amortization and impairments	16		11				40	32
Restructuring and other	0		320				2	375
Operating (loss) income	(50)		(369)				(142)	(526)
Interest expense	0		0				0	0
Gain (Loss) on Extinguishment of Debt							0	0
Gain (loss) on remeasurement of debt	0		0				0	0
Other income (expense), net	14		16				50	49
Net (loss) income before equity in income of subsidiaries and income taxes	(36)		(353)				(92)	(477)
Equity in (loss) income of subsidiaries	36		0				12	(60)
Income tax benefit (expense)	14		1				(7)	(22)
Net income (loss)	14						(87)
Less: Net income attributable to noncontrolling interest	0						0
Net Income (Loss) Attributable to Parent	14		(352)				(87)	(559)
Other comprehensive loss			(5)					(37)
Other Comprehensive Income (Loss), Net of Tax	(35)						(35)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(21)						(122)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	0						0
Comprehensive (loss) income attributable to SGC	(21)		(357)				(122)	(596)
Reportable Legal Entities | Guarantor Subsidiaries
Condensed Financial Statements
Revenue	376		404				1,092	1,196
Cost of services, cost of product sales and cost of instant products(2)	119		119				329	369
Selling, general and administrative	55		57				162	166
Research and development	22		21				64	66
Depreciation, amortization and impairments	99		106				302	339
Restructuring and other	2		4				5	8
Operating (loss) income	79		97				230	248
Interest expense	0		0				0	0
Gain (Loss) on Extinguishment of Debt							0	0
Gain (loss) on remeasurement of debt	0		0				0	0
Other income (expense), net	(117)		(123)				(360)	(375)
Net (loss) income before equity in income of subsidiaries and income taxes	(38)		(26)				(130)	(127)
Equity in (loss) income of subsidiaries	22		(10)				45	(17)
Income tax benefit (expense)	8		6				30	27
Net income (loss)	(8)						(55)
Less: Net income attributable to noncontrolling interest	0						0
Net Income (Loss) Attributable to Parent	(8)		(30)				(55)	(117)
Other comprehensive loss			(10)					(23)
Other Comprehensive Income (Loss), Net of Tax	(1)						(2)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(9)						(57)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	0						0
Comprehensive (loss) income attributable to SGC	(9)		(40)				(57)	(140)
Reportable Legal Entities | Non-Guarantor Subsidiaries
Condensed Financial Statements
Revenue	419		361				1,211	1,107
Cost of services, cost of product sales and cost of instant products(2)	170		160				498	472
Selling, general and administrative	88		76				276	238
Research and development	24		29				75	85
Depreciation, amortization and impairments	44		45				136	143
Restructuring and other	8		12				15	42
Operating (loss) income	85		39				211	127
Interest expense	0		0				0	0
Gain (Loss) on Extinguishment of Debt							0	0
Gain (loss) on remeasurement of debt	0		0				0	0
Other income (expense), net	(27)		(19)				(63)	(59)
Net (loss) income before equity in income of subsidiaries and income taxes	58		20				148	68
Equity in (loss) income of subsidiaries	0		0				0	0
Income tax benefit (expense)	(11)		(6)				(32)	(18)
Net income (loss)	47						116
Less: Net income attributable to noncontrolling interest	4						6
Net Income (Loss) Attributable to Parent	43		14				110	50
Other comprehensive loss			(2)					(48)
Other Comprehensive Income (Loss), Net of Tax	(61)						(56)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(14)						60
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	4						6
Comprehensive (loss) income attributable to SGC	(18)		12				54	2
Eliminating Entries
Condensed Financial Statements
Revenue	(79)		(82)				(210)	(229)
Cost of services, cost of product sales and cost of instant products(2)	(65)		(68)				(170)	(190)
Selling, general and administrative	(11)		(13)				(32)	(40)
Research and development	0		0				0	1
Depreciation, amortization and impairments	(5)		(5)				(14)	(11)
Restructuring and other	0		0				0	(1)
Operating (loss) income	2		4				6	12
Interest expense	0		0				0	0
Gain (Loss) on Extinguishment of Debt							0	0
Gain (loss) on remeasurement of debt	0		0				0	0
Other income (expense), net	0		0				0	0
Net (loss) income before equity in income of subsidiaries and income taxes	2		4				6	12
Equity in (loss) income of subsidiaries	(67)		6				(75)	55
Income tax benefit (expense)	0		0				0	0
Net income (loss)	(65)						(69)
Less: Net income attributable to noncontrolling interest	0						0
Net Income (Loss) Attributable to Parent	(65)		10				(69)	67
Other comprehensive loss			1					48
Other Comprehensive Income (Loss), Net of Tax	32						34
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(33)						(35)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	0						0
Comprehensive (loss) income attributable to SGC	$ (33)		$ 11				$ (35)	$ 115