Financial Information for Guarantor Subsidiaries and Non-Guarantor Subsidiaries - Supplemental Condensed Consolidating Statement of Operations and Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Financial Statements
Revenue	$ 725.4	$ 682.0
Cost of services, cost of product sales and cost of instant games	280.0	256.3
Selling, general and administrative	140.7	142.3
Research and development	42.4	49.8
Depreciation, amortization and impairments	165.1	180.6
Restructuring and other	9.2	2.7
Operating (loss) income	88.0	50.3
Interest (expense) income	(159.4)	(165.7)
Loss on extinguishment and modification of debt	(29.7)	0.0
Other (expense) income, net	17.0	3.9
Net (loss) income before equity in income of subsidiaries and income taxes	(84.1)	(111.5)
Equity in income of subsidiaries	0.0	0.0
Income tax (expense) benefit	(16.7)	19.2
Net (loss) income	(100.8)	(92.3)
Other comprehensive income	36.1	(2.4)
Comprehensive (loss) income	(64.7)	(94.7)
Eliminating Entries
Condensed Financial Statements
Revenue	(57.0)	(59.2)
Cost of services, cost of product sales and cost of instant games	(48.4)	(59.2)
Selling, general and administrative	(9.7)	0.0
Research and development	0.0	0.0
Depreciation, amortization and impairments	(2.4)	0.0
Restructuring and other	0.0	0.0
Operating (loss) income	3.5	0.0
Interest (expense) income	0.0	0.0
Loss on extinguishment and modification of debt	0.0
Other (expense) income, net	0.0	0.0
Net (loss) income before equity in income of subsidiaries and income taxes	3.5	0.0
Equity in income of subsidiaries	(37.4)	6.1
Income tax (expense) benefit	0.0	0.0
Net (loss) income	(33.9)	6.1
Other comprehensive income	(55.0)	(4.4)
Comprehensive (loss) income	(88.9)	1.7
SGC (Parent and Issuer) | Reportable Legal Entities
Condensed Financial Statements
Revenue	0.0	0.0
Cost of services, cost of product sales and cost of instant games	0.0	0.0
Selling, general and administrative	29.7	24.0
Research and development	0.5	0.9
Depreciation, amortization and impairments	20.3	12.8
Restructuring and other	3.8	0.0
Operating (loss) income	(54.3)	(37.7)
Interest (expense) income	(4.5)	(5.3)
Loss on extinguishment and modification of debt	(1.1)
Other (expense) income, net	(20.8)	(25.6)
Net (loss) income before equity in income of subsidiaries and income taxes	(80.7)	(68.6)
Equity in income of subsidiaries	4.7	(45.9)
Income tax (expense) benefit	(24.8)	22.2
Net (loss) income	(100.8)	(92.3)
Other comprehensive income	36.1	(2.4)
Comprehensive (loss) income	(64.7)	(94.7)
SGI (Issuer) | Reportable Legal Entities
Condensed Financial Statements
Revenue	118.0	115.3
Cost of services, cost of product sales and cost of instant games	82.9	82.9
Selling, general and administrative	9.5	11.3
Research and development	1.4	2.3
Depreciation, amortization and impairments	7.5	10.7
Restructuring and other	0.2	0.0
Operating (loss) income	16.5	8.1
Interest (expense) income	(154.6)	(160.5)
Loss on extinguishment and modification of debt	(28.6)
Other (expense) income, net	50.7	50.3
Net (loss) income before equity in income of subsidiaries and income taxes	(116.0)	(102.1)
Equity in income of subsidiaries	17.3	18.9
Income tax (expense) benefit	43.4	0.0
Net (loss) income	(55.3)	(83.2)
Other comprehensive income	4.0	(0.3)
Comprehensive (loss) income	(51.3)	(83.5)
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Financial Statements
Revenue	399.8	361.5
Cost of services, cost of product sales and cost of instant games	123.7	96.7
Selling, general and administrative	48.8	53.5
Research and development	34.2	35.9
Depreciation, amortization and impairments	111.9	126.2
Restructuring and other	4.2	0.8
Operating (loss) income	77.0	48.4
Interest (expense) income	0.0	0.0
Loss on extinguishment and modification of debt	0.0
Other (expense) income, net	(25.5)	(23.1)
Net (loss) income before equity in income of subsidiaries and income taxes	51.5	25.3
Equity in income of subsidiaries	15.4	20.9
Income tax (expense) benefit	(20.6)	0.0
Net (loss) income	46.3	46.2
Other comprehensive income	21.5	1.9
Comprehensive (loss) income	67.8	48.1
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Financial Statements
Revenue	264.6	264.4
Cost of services, cost of product sales and cost of instant games	121.8	135.9
Selling, general and administrative	62.4	53.5
Research and development	6.3	10.7
Depreciation, amortization and impairments	27.8	30.9
Restructuring and other	1.0	1.9
Operating (loss) income	45.3	31.5
Interest (expense) income	(0.3)	0.1
Loss on extinguishment and modification of debt	0.0
Other (expense) income, net	12.6	2.3
Net (loss) income before equity in income of subsidiaries and income taxes	57.6	33.9
Equity in income of subsidiaries	0.0	0.0
Income tax (expense) benefit	(14.7)	(3.0)
Net (loss) income	42.9	30.9
Other comprehensive income	29.5	2.8
Comprehensive (loss) income	$ 72.4	$ 33.7