Condensed Consolidating Financial Statements - Statement of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 01, 2018	Mar. 26, 2017
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	$ 6.5	$ (5.4)
Investing activities:
Cash paid for acquisitions, net of cash acquired	0.0
Investment in affiliated companies	0.0	0.0
Change in restricted cash	0.0
Proceeds from sale of assets	0.0
Capital expenditures	(6.7)	(5.1)
Net cash used in investing activities from continuing operations	(6.7)	(5.1)
Financing activities:
Extinguishment of long-term debt	0.0	(64.0)
Repayment of debt	(0.2)	(0.3)
Debt issuance costs	(0.1)	0.0
Proceeds from the issuance of common stock	(1.1)	81.9
Proceeds from exercise of restricted stock units, employee stock options, and employee stock purchase plan	1.8	0.8
Financing from affiliated companies		0.0
Net cash provided by financing activities from continuing operations	0.4	18.4
Net cash flows of continuing operations	0.2	7.9
Net operating cash flows of discontinued operations	(3.1)	(4.3)
Net investing cash flows of discontinued operations	0.0	(0.2)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0.2	0.0
Net increase (decrease) in cash, cash equivalents and restricted cash	(2.7)	3.4
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	0.0	0.0
Investing activities:
Cash paid for acquisitions, net of cash acquired	0.0
Investment in affiliated companies	0.0	14.6
Change in restricted cash	0.0
Proceeds from sale of assets	0.0
Capital expenditures	0.0	0.0
Net cash used in investing activities from continuing operations	0.0	14.6
Financing activities:
Extinguishment of long-term debt		0.0
Repayment of debt	0.0	0.0
Debt issuance costs	0.0
Proceeds from the issuance of common stock	0.0	0.0
Proceeds from exercise of restricted stock units, employee stock options, and employee stock purchase plan	0.0	0.0
Financing from affiliated companies		(14.6)
Net cash provided by financing activities from continuing operations	0.0	(14.6)
Net cash flows of continuing operations	0.0	0.0
Net operating cash flows of discontinued operations	0.0	0.0
Net investing cash flows of discontinued operations		0.0
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0.0
Net increase (decrease) in cash, cash equivalents and restricted cash	0.0	0.0
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	(3.1)	(1.5)
Investing activities:
Cash paid for acquisitions, net of cash acquired	0.0
Investment in affiliated companies	0.0	(14.6)
Change in restricted cash	0.0
Proceeds from sale of assets	0.0
Capital expenditures	0.0	0.0
Net cash used in investing activities from continuing operations	0.0	(14.6)
Financing activities:
Extinguishment of long-term debt		(64.0)
Repayment of debt	0.0	0.0
Debt issuance costs	(0.1)
Proceeds from the issuance of common stock	(1.1)	81.9
Proceeds from exercise of restricted stock units, employee stock options, and employee stock purchase plan	1.8	0.8
Financing from affiliated companies		0.0
Net cash provided by financing activities from continuing operations	0.6	18.7
Net cash flows of continuing operations	(2.5)	2.6
Net operating cash flows of discontinued operations	(0.4)	(0.4)
Net investing cash flows of discontinued operations		(0.2)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0.0
Net increase (decrease) in cash, cash equivalents and restricted cash	(2.9)	2.0
Subsidiary Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	10.2	(4.7)
Investing activities:
Cash paid for acquisitions, net of cash acquired	(1.9)
Investment in affiliated companies	0.0	0.0
Change in restricted cash	0.0
Proceeds from sale of assets	0.0
Capital expenditures	(6.2)	(4.9)
Net cash used in investing activities from continuing operations	(8.1)	(4.9)
Financing activities:
Extinguishment of long-term debt		0.0
Repayment of debt	0.0	0.0
Debt issuance costs	0.0
Proceeds from the issuance of common stock	0.0	0.0
Proceeds from exercise of restricted stock units, employee stock options, and employee stock purchase plan	0.0	0.0
Financing from affiliated companies		14.6
Net cash provided by financing activities from continuing operations	0.0	14.6
Net cash flows of continuing operations	2.1	5.0
Net operating cash flows of discontinued operations	(2.7)	(3.9)
Net investing cash flows of discontinued operations		0.0
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0.0
Net increase (decrease) in cash, cash equivalents and restricted cash	(0.6)	1.1
Non-Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	(0.6)	0.8
Investing activities:
Cash paid for acquisitions, net of cash acquired	1.9
Investment in affiliated companies	0.0	0.0
Change in restricted cash	0.0
Proceeds from sale of assets	0.0
Capital expenditures	(0.5)	(0.2)
Net cash used in investing activities from continuing operations	1.4	(0.2)
Financing activities:
Extinguishment of long-term debt		0.0
Repayment of debt	(0.2)	(0.3)
Debt issuance costs	0.0
Proceeds from the issuance of common stock	0.0	0.0
Proceeds from exercise of restricted stock units, employee stock options, and employee stock purchase plan	0.0	0.0
Financing from affiliated companies		0.0
Net cash provided by financing activities from continuing operations	(0.2)	(0.3)
Net cash flows of continuing operations	0.6	0.3
Net operating cash flows of discontinued operations	0.0	0.0
Net investing cash flows of discontinued operations		0.0
Effect of exchange rate changes on cash, cash equivalents and restricted cash	0.2
Net increase (decrease) in cash, cash equivalents and restricted cash	$ 0.8	$ 0.3