CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Unaudited) - USD ($) $ in Millions	Total	Redeemable Noncontrolling Interest	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance, beginning of period (in shares) at Dec. 31, 2017			103,300,000
Balance, beginning of period at Dec. 31, 2017	$ 511.5		$ 0.0	$ 1,233.7	$ (1.4)	$ (720.8)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	1.7			1.7
Issuance of common stock for employee stock purchase plan, options and warrants (in shares)			200,000
Issuance of common stock for employee stock purchase plan, options and warrants	1.8			1.8
Net income (loss)	(2.2)					(2.2)
Other comprehensive income (loss), net of tax	(0.1)				(0.1)
Balance, end of period (in shares) at Apr. 01, 2018			103,500,000
Balance, end of period at Apr. 01, 2018	512.5		$ 0.0	1,237.2	(1.5)	(723.2)
Balance, beginning of period at Dec. 30, 2018	0.0	$ 0.0
Increase (Decrease) in Temporary Equity [Roll Forward]
Changes in noncontrolling interest		15.0
Balance, end of period at Mar. 31, 2019	$ 15.0	$ 15.0
Balance, beginning of period (in shares) at Dec. 30, 2018	103,766,899		103,800,000
Balance, beginning of period at Dec. 30, 2018	$ 519.3		$ 0.0	1,244.5	(0.7)	(724.5)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	2.6			2.6
Issuance of common stock for employee stock purchase plan, options and warrants (in shares)			200,000
Issuance of common stock for employee stock purchase plan, options and warrants	1.7			1.7
Restricted stock issued and related taxes (in shares)			100,000
Restricted stock issued and related taxes	(0.8)			(0.8)
Issuance of common stock for acquisitions (in shares)			1,800,000
Issuance of common stock for acquisitions	27.0			27.0
Net income (loss)	3.1					3.1
Other comprehensive income (loss), net of tax	$ 0.0
Balance, end of period (in shares) at Mar. 31, 2019	105,885,792		105,900,000
Balance, end of period at Mar. 31, 2019	$ 552.9		$ 0.0	$ 1,275.0	$ (0.7)	$ (721.4)