Condensed Consolidating Financial Statements - Statement of Operations and Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 24, 2012	Jun. 30, 2013	Jun. 24, 2012
Condensed Financial Statements, Captions [Line Items]
Service revenues	$ 110.2	$ 112.1	$ 226.2	$ 214.2
Product sales	125.0	107.7	262.3	215.1
Total revenues	235.2	219.8	488.5	429.3
Cost of service revenues	83.3	86.7	171.9	166.5
Cost of product sales	91.5	75.4	190.4	147.7
Total costs	174.8	162.1	362.3	314.2
Gross profit	60.4	57.7	126.2	115.1
Selling, general and administrative expenses	46.7	45.5	96.2	90.2
Research and development expenses	4.8	4.8	9.7	8.4
Operating income from continuing operations	8.9	7.4	20.3	16.5
Other income (expense):
Interest expense, net	(16.3)	(16.2)	(32.5)	(32.3)
Other income (expense), net	0.2	0.5	(0.6)	0.9
Total other expense, net	(16.1)	(15.7)	(33.1)	(31.4)
Loss from continuing operations before income taxes	(7.2)	(8.3)	(12.8)	(14.9)
Provision (benefit) for income taxes from continuing operations	(0.1)	6.6	2.7	2.5
Loss from continuing operations	(7.1)	(14.9)	(15.5)	(17.4)
Loss from discontinued operations	(2.5)	(2.3)	(4.4)	(2.8)
Equity in net income (loss) of subsidiaries	0	0	0	0
Net loss	(9.6)	(17.2)	(19.9)	(20.2)
Comprehensive income (loss)	(9.6)	(17.4)	(19.8)	(20.4)
Parent Company
Condensed Financial Statements, Captions [Line Items]
Service revenues	0	0	0	0
Product sales	0	0	0	0
Total revenues	0	0	0	0
Cost of service revenues	0	0	0	0
Cost of product sales	0	0	0	0
Total costs	0	0	0	0
Gross profit	0	0	0	0
Selling, general and administrative expenses	1.1	2.6	3.7	4.8
Research and development expenses	0	0	0	0
Operating income from continuing operations	(1.1)	(2.6)	(3.7)	(4.8)
Other income (expense):
Interest expense, net	(16.1)	(16.1)	(32.2)	(32.1)
Other income (expense), net	0	0	0	0.3
Total other expense, net	(16.1)	(16.1)	(32.2)	(31.8)
Loss from continuing operations before income taxes	(17.2)	(18.7)	(35.9)	(36.6)
Provision (benefit) for income taxes from continuing operations	0.2	0	0.5	0
Loss from continuing operations	(17.4)	(18.7)	(36.4)	(36.6)
Loss from discontinued operations	0.1	0	0.1	0
Equity in net income (loss) of subsidiaries	7.7	1.5	16.4	16.4
Net loss	(9.6)	(17.2)	(19.9)	(20.2)
Comprehensive income (loss)	(9.6)	(17.4)	(19.8)	(20.4)
Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Service revenues	109.3	111.5	224.8	213.0
Product sales	110.9	96.6	234.2	192.6
Total revenues	220.2	208.1	459.0	405.6
Cost of service revenues	82.6	86.2	170.8	165.7
Cost of product sales	82.8	69.2	173.5	134.9
Total costs	165.4	155.4	344.3	300.6
Gross profit	54.8	52.7	114.7	105.0
Selling, general and administrative expenses	42.4	40.0	86.2	78.9
Research and development expenses	4.5	4.6	9.0	7.9
Operating income from continuing operations	7.9	8.1	19.5	18.2
Other income (expense):
Interest expense, net	0	0.1	0	0.1
Other income (expense), net	0.1	0.2	0.1	0.1
Total other expense, net	0.1	0.3	0.1	0.2
Loss from continuing operations before income taxes	8.0	8.4	19.6	18.4
Provision (benefit) for income taxes from continuing operations	(0.4)	(5.7)	2.0	2.3
Loss from continuing operations	8.4	14.1	17.6	16.1
Loss from discontinued operations	(2.7)	(2.2)	(4.5)	(2.8)
Equity in net income (loss) of subsidiaries	2.0	1.0	3.3	3.0
Net loss	7.7	12.9	16.4	16.3
Comprehensive income (loss)	7.7	1.7	16.4	16.3
Non-Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Service revenues	0.9	0.6	1.4	1.2
Product sales	18.8	14.7	37.6	29.0
Total revenues	19.7	15.3	39.0	30.2
Cost of service revenues	0.7	0.5	1.1	0.8
Cost of product sales	13.4	9.8	26.4	19.3
Total costs	14.1	10.3	27.5	20.1
Gross profit	5.6	5.0	11.5	10.1
Selling, general and administrative expenses	3.2	2.9	6.3	6.5
Research and development expenses	0.3	0.2	0.7	0.5
Operating income from continuing operations	2.1	1.9	4.5	3.1
Other income (expense):
Interest expense, net	(0.2)	(0.2)	(0.3)	(0.3)
Other income (expense), net	0.1	0.3	(0.7)	0.5
Total other expense, net	(0.1)	0.1	(1.0)	0.2
Loss from continuing operations before income taxes	2.0	2.0	3.5	3.3
Provision (benefit) for income taxes from continuing operations	0.1	(0.9)	0.2	0.2
Loss from continuing operations	1.9	2.9	3.3	3.1
Loss from discontinued operations	0.1	(0.1)	0	0
Equity in net income (loss) of subsidiaries	0	0	0	0
Net loss	2.0	2.8	3.3	3.1
Comprehensive income (loss)	2.0	1.1	3.2	3.2
Eliminations
Condensed Financial Statements, Captions [Line Items]
Service revenues	0	0	0	0
Product sales	(4.7)	(3.6)	(9.5)	(6.5)
Total revenues	(4.7)	(3.6)	(9.5)	(6.5)
Cost of service revenues	0	0	0	0
Cost of product sales	(4.7)	(3.6)	(9.5)	(6.5)
Total costs	(4.7)	(3.6)	(9.5)	(6.5)
Gross profit	0	0	0	0
Selling, general and administrative expenses	0	0	0	0
Research and development expenses	0	0	0	0
Operating income from continuing operations	0	0	0	0
Other income (expense):
Interest expense, net	0	0	0	0
Other income (expense), net	0	0	0	0
Total other expense, net	0	0	0	0
Loss from continuing operations before income taxes	0	0	0	0
Provision (benefit) for income taxes from continuing operations	0	0	0	0
Loss from continuing operations	0	0	0	0
Loss from discontinued operations	0	0	0	0
Equity in net income (loss) of subsidiaries	(9.7)	(2.5)	(19.7)	(19.4)
Net loss	(9.7)	(2.5)	(19.7)	(19.4)
Comprehensive income (loss)	$ (9.7)	$ (2.8)	$ (19.6)	$ (19.5)