Condensed Consolidating Financial Statements - Statement of Operations and Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 28, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 29, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Condensed Financial Statements, Captions [Line Items]
Service revenues									$ 390.8	$ 443.6	$ 450.0
Product sales									477.2	507.0	519.2
Total revenues	221.5	217.1	229.3	200.1	235.7	226.4	235.2	253.3	868.0	950.6	969.2
Cost of service revenues									304.6	335.2	350.8
Cost of product sales									345.2	375.4	361.2
Total costs									649.8	710.6	712.0
Gross profit	56.2	53.0	56.4	52.6	61.5	52.3	60.4	65.8	218.2	240.0	257.2
Selling, general and administrative expenses									175.3	186.8	192.5
Impairment of goodwill and intangible assets									0	0	96.6
Research and development expenses									23.0	21.4	17.8
Operating income (loss) from continuing operations	10.7	1.2	4.7	3.3	5.4	6.1	8.9	11.4	19.9	31.8	(49.7)
Other income (expense):
Interest expense, net									(54.3)	(63.7)	(66.1)
Loss on extinguishment of debt		(39.1)							(39.1)	0	0
Other income, net									0.6	0	1.3
Total other expense, net									(92.8)	(63.7)	(64.8)
Loss from continuing operations before income taxes									(72.9)	(31.9)	(114.5)
Provision (benefit) for income taxes from continuing operations	1.4	(0.2)	1.6	2.3	(2.9)	0.2	(0.1)	2.8	5.1	0	(1.6)
Income (loss) from continuing operations									(78.0)	(31.9)	(112.9)
Loss from discontinued operations									0	(5.3)	(1.5)
Equity in net income (loss) of subsidiaries									0	0	0
Net loss	(2.2)	(10.9)	(49.9)	(15.0)	(7.4)	(9.9)	(9.6)	(10.3)	(78.0)	(37.2)	(114.4)
Comprehensive income (loss)									(78.9)	(37.2)	(115.0)
Parent Company
Condensed Financial Statements, Captions [Line Items]
Service revenues									0	0	0
Product sales									0	0	0
Total revenues									0	0	0
Cost of service revenues									0	0	0
Cost of product sales									0	0	0
Total costs									0	0	0
Gross profit									0	0	0
Selling, general and administrative expenses									8.4	5.5	7.4
Impairment of goodwill and intangible assets									0	0	0
Research and development expenses									0	0	0
Operating income (loss) from continuing operations									(8.4)	(5.5)	(7.4)
Other income (expense):
Interest expense, net									(54.3)	(65.6)	(65.9)
Loss on extinguishment of debt									(39.1)
Other income, net									0	0	0.3
Total other expense, net									(93.4)	(65.6)	(65.6)
Loss from continuing operations before income taxes									(101.8)	(71.1)	(73.0)
Provision (benefit) for income taxes from continuing operations									0.6	0.6	20.8
Income (loss) from continuing operations									(102.4)	(71.7)	(93.8)
Loss from discontinued operations									0.3	0.1	(0.1)
Equity in net income (loss) of subsidiaries									24.1	34.4	(20.5)
Net loss									(78.0)	(37.2)	(114.4)
Comprehensive income (loss)									(78.9)	(37.2)	(115.0)
Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Service revenues									380.8	438.2	448.5
Product sales									417.1	448.6	470.0
Total revenues									797.9	886.8	918.5
Cost of service revenues									297.0	331.3	350.0
Cost of product sales									308.8	338.9	333.8
Total costs									605.8	670.2	683.8
Gross profit									192.1	216.6	234.7
Selling, general and administrative expenses									152.9	167.2	171.2
Impairment of goodwill and intangible assets									0	0	96.6
Research and development expenses									21.5	20.2	16.9
Operating income (loss) from continuing operations									17.7	29.2	(50.0)
Other income (expense):
Interest expense, net									0.3	2.3	0.3
Loss on extinguishment of debt									0
Other income, net									(1.9)	(0.3)	0.1
Total other expense, net									(1.6)	2.0	0.4
Loss from continuing operations before income taxes									16.1	31.2	(49.6)
Provision (benefit) for income taxes from continuing operations									3.3	(0.7)	(22.8)
Income (loss) from continuing operations									12.8	31.9	(26.8)
Loss from discontinued operations									(0.3)	(5.4)	(2.2)
Equity in net income (loss) of subsidiaries									11.6	7.9	8.3
Net loss									24.1	34.4	(20.7)
Comprehensive income (loss)									23.6	34.4	20.9
Non-Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Service revenues									10.0	5.4	1.5
Product sales									69.0	75.3	64.5
Total revenues									79.0	80.7	66.0
Cost of service revenues									7.6	3.9	0.8
Cost of product sales									45.3	53.4	42.7
Total costs									52.9	57.3	43.5
Gross profit									26.1	23.4	22.5
Selling, general and administrative expenses									14.0	14.1	13.9
Impairment of goodwill and intangible assets									0	0	0
Research and development expenses									1.5	1.2	0.9
Operating income (loss) from continuing operations									10.6	8.1	7.7
Other income (expense):
Interest expense, net									(0.3)	(0.4)	(0.5)
Loss on extinguishment of debt									0
Other income, net									2.5	0.3	0.9
Total other expense, net									2.2	(0.1)	0.4
Loss from continuing operations before income taxes									12.8	8.0	8.1
Provision (benefit) for income taxes from continuing operations									1.2	0.1	0.4
Income (loss) from continuing operations									11.6	7.9	7.7
Loss from discontinued operations									0	0	0.8
Equity in net income (loss) of subsidiaries									0	0	0
Net loss									11.6	7.9	8.5
Comprehensive income (loss)									11.2	7.9	9.4
Eliminations
Condensed Financial Statements, Captions [Line Items]
Service revenues									0	0	0
Product sales									(8.9)	(16.9)	(15.3)
Total revenues									(8.9)	(16.9)	(15.3)
Cost of service revenues									0	0	0
Cost of product sales									(8.9)	(16.9)	(15.3)
Total costs									(8.9)	(16.9)	(15.3)
Gross profit									0	0	0
Selling, general and administrative expenses									0	0	0
Impairment of goodwill and intangible assets									0	0	0
Research and development expenses									0	0	0
Operating income (loss) from continuing operations									0	0	0
Other income (expense):
Interest expense, net									0	0	0
Loss on extinguishment of debt									0
Other income, net									0	0	0
Total other expense, net									0	0	0
Loss from continuing operations before income taxes									0	0	0
Provision (benefit) for income taxes from continuing operations									0	0	0
Income (loss) from continuing operations									0	0	0
Loss from discontinued operations									0	0	0
Equity in net income (loss) of subsidiaries									(35.7)	(42.3)	12.2
Net loss									(35.7)	(42.3)	12.2
Comprehensive income (loss)									$ (34.8)	$ (42.3)	$ 11.5