Condensed Consolidating Financial Statements - Statement of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 26, 2017	Mar. 27, 2016
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	$ (8.7)	$ (11.5)
Investing activities:
Investment in affiliated companies	0.0	0.0
Capital expenditures	(5.2)	(2.1)
Net cash used in investing activities from continuing operations	(5.2)	(2.1)
Financing activities:
Extinguishment of long-term debt	(64.0)	0.0
Repayment of debt	(0.3)	(0.3)
Proceeds from the issuance of common stock	81.9	0.0
Proceeds from exercise of restricted stock units, employee stock options, and employee stock purchase plan	0.8	1.2
Financing from affiliated companies	0.0	0.0
Net cash provided by financing activities from continuing operations	18.4	0.9
Net cash flows of continuing operations	4.5	(12.7)
Net operating cash flows of discontinued operations	0.0	(0.4)
Net investing cash flows of discontinued operations	(0.2)	4.7
Net increase (decrease) in cash and cash equivalents	4.3	(8.4)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	0.0	0.0
Investing activities:
Investment in affiliated companies	15.0	15.8
Capital expenditures	0.0	0.0
Net cash used in investing activities from continuing operations	15.0	15.8
Financing activities:
Extinguishment of long-term debt	0.0
Repayment of debt	0.0	0.0
Proceeds from the issuance of common stock	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	(15.0)	(15.8)
Net cash provided by financing activities from continuing operations	(15.0)	(15.8)
Net cash flows of continuing operations	0.0	0.0
Net operating cash flows of discontinued operations		0.0
Net investing cash flows of discontinued operations	0.0	0.0
Net increase (decrease) in cash and cash equivalents	0.0	0.0
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	(1.8)	3.9
Investing activities:
Investment in affiliated companies	(15.0)	(15.8)
Capital expenditures	0.0	(0.3)
Net cash used in investing activities from continuing operations	(15.0)	(16.1)
Financing activities:
Extinguishment of long-term debt	(64.0)
Repayment of debt	0.0	0.0
Proceeds from the issuance of common stock	81.9
Proceeds from exercise of restricted stock units, employee stock options, and employee stock purchase plan	0.8	1.2
Financing from affiliated companies	0.0	0.0
Net cash provided by financing activities from continuing operations	18.7	1.2
Net cash flows of continuing operations	1.9	(11.0)
Net operating cash flows of discontinued operations		(0.4)
Net investing cash flows of discontinued operations	(0.2)	4.7
Net increase (decrease) in cash and cash equivalents	1.7	(6.7)
Subsidiary Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	(7.7)	(15.3)
Investing activities:
Investment in affiliated companies	0.0	0.0
Capital expenditures	(5.0)	(1.4)
Net cash used in investing activities from continuing operations	(5.0)	(1.4)
Financing activities:
Extinguishment of long-term debt	0.0
Repayment of debt	0.0	0.0
Proceeds from the issuance of common stock	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	15.0	15.8
Net cash provided by financing activities from continuing operations	15.0	15.8
Net cash flows of continuing operations	2.3	(0.9)
Net operating cash flows of discontinued operations		0.0
Net investing cash flows of discontinued operations	0.0	0.0
Net increase (decrease) in cash and cash equivalents	2.3	(0.9)
Non-Guarantors on a Combined Basis
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities from continuing operations	0.8	(0.1)
Investing activities:
Investment in affiliated companies	0.0	0.0
Capital expenditures	(0.2)	(0.4)
Net cash used in investing activities from continuing operations	(0.2)	(0.4)
Financing activities:
Extinguishment of long-term debt	0.0
Repayment of debt	(0.3)	(0.3)
Proceeds from the issuance of common stock	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	0.0
Net cash provided by financing activities from continuing operations	(0.3)	(0.3)
Net cash flows of continuing operations	0.3	(0.8)
Net operating cash flows of discontinued operations		0.0
Net investing cash flows of discontinued operations	0.0	0.0
Net increase (decrease) in cash and cash equivalents	$ 0.3	$ (0.8)