Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 26, 2016	Jun. 28, 2015	Jun. 26, 2016	Jun. 28, 2015
Condensed Financial Statements, Captions [Line Items]
Service revenues	$ 88.2	$ 88.8	$ 170.8	$ 176.1
Product sales	80.0	71.7	150.4	141.3
Total revenues	168.2	160.5	321.2	317.4
Cost of service revenues	64.4	67.1	124.7	133.1
Cost of product sales	58.6	52.5	115.4	105.1
Total costs	123.0	119.6	240.1	238.2
Gross profit	45.2	40.9	81.1	79.2
Selling, general and administrative expenses	41.2	40.3	84.4	78.6
Research and development expenses	4.0	4.3	6.9	8.2
Operating loss from continuing operations	0.0	(3.7)	(10.2)	(7.6)
Other income (expense):
Interest income (expense), net	(8.7)	(8.9)	(17.4)	(17.7)
Other income (expense), net	0.2	(1.0)	0.5	(0.9)
Total other expense, net	(8.5)	(9.9)	(16.9)	(18.6)
Loss from continuing operations before income taxes	(8.5)	(13.6)	(27.1)	(26.2)
Provision for income taxes from continuing operations	1.8	2.3	5.4	4.2
Loss from continuing operations	(10.3)	(15.9)	(32.5)	(30.4)
Income (loss) from discontinued operations	(0.1)	0.9	(0.1)	(0.9)
Equity in net income (loss) of subsidiaries	0.0	0.0	0.0	0.0
Net loss	(10.4)	(15.0)	(32.6)	(31.3)
Comprehensive income (loss)	(10.5)	(14.7)	(32.7)	(31.2)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Service revenues	0.0	0.0	0.0	0.0
Product sales	(1.9)	(3.3)	(3.6)	(6.2)
Total revenues	(1.9)	(3.3)	(3.6)	(6.2)
Cost of service revenues	0.0	0.0	0.0	0.0
Cost of product sales	(1.9)	(3.3)	(3.6)	(6.2)
Total costs	(1.9)	(3.3)	(3.6)	(6.2)
Gross profit	0.0	0.0	0.0	0.0
Selling, general and administrative expenses	0.0	0.0	0.0	0.0
Research and development expenses	0.0	0.0	0.0	0.0
Operating loss from continuing operations	0.0	0.0	0.0	0.0
Other income (expense):
Interest income (expense), net	0.0	0.0	0.0	0.0
Other income (expense), net	0.0	0.0	0.0	0.0
Total other expense, net	0.0	0.0	0.0	0.0
Loss from continuing operations before income taxes	0.0	0.0	0.0	0.0
Provision for income taxes from continuing operations	0.0	0.0	0.0	0.0
Loss from continuing operations	0.0	0.0	0.0	0.0
Income (loss) from discontinued operations	0.0	0.0	0.0	0.0
Equity in net income (loss) of subsidiaries	(2.5)	(2.1)	7.8	(7.7)
Net loss	(2.5)	(2.1)	7.8	(7.7)
Comprehensive income (loss)	(2.4)	(0.6)	7.9	(7.8)
Parent Company
Condensed Financial Statements, Captions [Line Items]
Service revenues	0.0	0.0	0.0	0.0
Product sales	0.0	0.0	0.0	0.0
Total revenues	0.0	0.0	0.0	0.0
Cost of service revenues	0.0	0.0	0.0	0.0
Cost of product sales	0.0	0.0	0.0	0.0
Total costs	0.0	0.0	0.0	0.0
Gross profit	0.0	0.0	0.0	0.0
Selling, general and administrative expenses	2.5	0.7	3.8	5.8
Research and development expenses	0.0	0.0	0.0	0.0
Operating loss from continuing operations	(2.5)	(0.7)	(3.8)	(5.8)
Other income (expense):
Interest income (expense), net	(8.7)	(8.8)	(17.3)	(17.5)
Other income (expense), net	0.0	(1.4)	0.0	(1.4)
Total other expense, net	(8.7)	(10.2)	(17.3)	(18.9)
Loss from continuing operations before income taxes	(11.2)	(10.9)	(21.1)	(24.7)
Provision for income taxes from continuing operations	0.0	0.2	0.1	0.4
Loss from continuing operations	(11.2)	(11.1)	(21.2)	(25.1)
Income (loss) from discontinued operations	(0.1)	(3.5)	(0.1)	(6.8)
Equity in net income (loss) of subsidiaries	0.9	(0.4)	(11.3)	0.6
Net loss	(10.4)	(15.0)	(32.6)	(31.3)
Comprehensive income (loss)	(10.5)	(14.7)	(32.7)	(31.2)
Subsidiary Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Service revenues	82.3	84.7	159.7	170.2
Product sales	69.0	62.8	128.0	124.5
Total revenues	151.3	147.5	287.7	294.7
Cost of service revenues	60.0	63.9	116.7	128.6
Cost of product sales	50.2	46.7	98.2	93.8
Total costs	110.2	110.6	214.9	222.4
Gross profit	41.1	36.9	72.8	72.3
Selling, general and administrative expenses	36.2	37.5	75.8	68.5
Research and development expenses	3.9	4.1	6.8	7.9
Operating loss from continuing operations	1.0	(4.7)	(9.8)	(4.1)
Other income (expense):
Interest income (expense), net	0.0	(0.1)	(0.1)	(0.2)
Other income (expense), net	(0.2)	0.8	(0.2)	(2.2)
Total other expense, net	(0.2)	0.7	(0.3)	(2.4)
Loss from continuing operations before income taxes	0.8	(4.0)	(10.1)	(6.5)
Provision for income taxes from continuing operations	1.5	1.8	4.7	3.6
Loss from continuing operations	(0.7)	(5.8)	(14.8)	(10.1)
Income (loss) from discontinued operations	0.0	2.9	0.0	3.6
Equity in net income (loss) of subsidiaries	1.6	2.5	3.5	7.1
Net loss	0.9	(0.4)	(11.3)	0.6
Comprehensive income (loss)	0.9	(2.2)	(11.3)	0.6
Non-Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Service revenues	5.9	4.1	11.1	5.9
Product sales	12.9	12.2	26.0	23.0
Total revenues	18.8	16.3	37.1	28.9
Cost of service revenues	4.4	3.2	8.0	4.5
Cost of product sales	10.3	9.1	20.8	17.5
Total costs	14.7	12.3	28.8	22.0
Gross profit	4.1	4.0	8.3	6.9
Selling, general and administrative expenses	2.5	2.1	4.8	4.3
Research and development expenses	0.1	0.2	0.1	0.3
Operating loss from continuing operations	1.5	1.7	3.4	2.3
Other income (expense):
Interest income (expense), net	0.0	0.0	0.0	0.0
Other income (expense), net	0.4	(0.4)	0.7	2.7
Total other expense, net	0.4	(0.4)	0.7	2.7
Loss from continuing operations before income taxes	1.9	1.3	4.1	5.0
Provision for income taxes from continuing operations	0.3	0.3	0.6	0.2
Loss from continuing operations	1.6	1.0	3.5	4.8
Income (loss) from discontinued operations	0.0	1.5	0.0	2.3
Equity in net income (loss) of subsidiaries	0.0	0.0	0.0	0.0
Net loss	1.6	2.5	3.5	7.1
Comprehensive income (loss)	$ 1.5	$ 2.8	$ 3.4	$ 7.2