Condensed Consolidating Financial Statements - Statement of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2017	Mar. 27, 2016
Condensed Financial Statements, Captions [Line Items]
Service revenues	$ 85.0	$ 82.6
Product sales	82.8	70.4
Total revenues	167.8	153.0
Cost of service revenues	61.8	60.3
Cost of product sales	60.9	56.8
Total costs	122.7	117.1
Gross profit	45.1	35.9
Selling, general and administrative expenses	39.0	43.2
Research and development expenses	4.4	2.9
Operating income (loss) from continuing operations	1.7	(10.2)
Other income (expense):
Interest income (expense), net	(8.2)	(8.7)
Loss on extinguishment of debt	(2.1)	0.0
Other income (expense), net	0.2	0.3
Total other expense, net	(10.1)	(8.4)
Loss from continuing operations before income taxes	(8.4)	(18.6)
Provision (benefit) for income taxes from continuing operations	1.5	3.6
Loss from continuing operations	(9.9)	(22.2)
Income (loss) from discontinued operations	(0.1)	0.0
Equity in net income (loss) of subsidiaries	0.0	0.0
Net loss	(10.0)	(22.2)
Comprehensive income (loss)	(9.9)	(22.2)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Service revenues	0.0	0.0
Product sales	(3.2)	(1.7)
Total revenues	(3.2)	(1.7)
Cost of service revenues	0.0	0.0
Cost of product sales	(3.2)	(1.7)
Total costs	(3.2)	(1.7)
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 (loss) from continuing operations	0.0	0.0
Other income (expense):
Interest income (expense), net	0.0	0.0
Loss on extinguishment of debt	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
Income (loss) from discontinued operations	0.0
Equity in net income (loss) of subsidiaries	(2.3)	10.3
Net loss	(2.3)	10.3
Comprehensive income (loss)	(2.4)	10.3
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	2.1	1.3
Research and development expenses	0.0	0.0
Operating income (loss) from continuing operations	(2.1)	(1.3)
Other income (expense):
Interest income (expense), net	(8.2)	(8.6)
Loss on extinguishment of debt	(2.1)
Other income (expense), net	0.0	0.0
Total other expense, net	(10.3)	(8.6)
Loss from continuing operations before income taxes	(12.4)	(9.9)
Provision (benefit) for income taxes from continuing operations	0.1	0.1
Loss from continuing operations	(12.5)	(10.0)
Income (loss) from discontinued operations	(0.1)
Equity in net income (loss) of subsidiaries	2.6	(12.2)
Net loss	(10.0)	(22.2)
Comprehensive income (loss)	(9.9)	(22.2)
Subsidiary Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Service revenues	82.4	77.4
Product sales	73.3	59.0
Total revenues	155.7	136.4
Cost of service revenues	59.9	56.7
Cost of product sales	54.0	48.0
Total costs	113.9	104.7
Gross profit	41.8	31.7
Selling, general and administrative expenses	33.8	39.6
Research and development expenses	4.0	2.9
Operating income (loss) from continuing operations	4.0	(10.8)
Other income (expense):
Interest income (expense), net	0.0	(0.1)
Loss on extinguishment of debt	0.0
Other income (expense), net	0.0	0.0
Total other expense, net	0.0	(0.1)
Loss from continuing operations before income taxes	4.0	(10.9)
Provision (benefit) for income taxes from continuing operations	1.1	3.2
Loss from continuing operations	2.9	(14.1)
Income (loss) from discontinued operations	0.0
Equity in net income (loss) of subsidiaries	(0.3)	1.9
Net loss	2.6	(12.2)
Comprehensive income (loss)	2.6	(12.2)
Non-Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Service revenues	2.6	5.2
Product sales	12.7	13.1
Total revenues	15.3	18.3
Cost of service revenues	1.9	3.6
Cost of product sales	10.1	10.5
Total costs	12.0	14.1
Gross profit	3.3	4.2
Selling, general and administrative expenses	3.1	2.3
Research and development expenses	0.4	0.0
Operating income (loss) from continuing operations	(0.2)	1.9
Other income (expense):
Interest income (expense), net	0.0	0.0
Loss on extinguishment of debt	0.0
Other income (expense), net	0.2	0.3
Total other expense, net	0.2	0.3
Loss from continuing operations before income taxes	0.0	2.2
Provision (benefit) for income taxes from continuing operations	0.3	0.3
Loss from continuing operations	(0.3)	1.9
Income (loss) from discontinued operations	0.0
Equity in net income (loss) of subsidiaries	0.0	0.0
Net loss	(0.3)	1.9
Comprehensive income (loss)	$ (0.2)	$ 1.9