CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Millions	Total	Redeemable Noncontrolling Interest	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance, beginning of period at Dec. 31, 2017		$ 0.0
Balance, end of period at Apr. 01, 2018		0.0
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. 31, 2017		0.0
Balance, end of period at Jul. 01, 2018		0.0
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
Net income (loss)	(9.9)
Other comprehensive income (loss), net of tax	0.0
Balance, end of period (in shares) at Jul. 01, 2018			103,500,000
Balance, end of period at Jul. 01, 2018	506.5		$ 0.0	1,238.8	(1.4)	(730.9)
Balance, beginning of period at Apr. 01, 2018		0.0
Balance, end of period at Jul. 01, 2018		0.0
Balance, beginning of period (in shares) at Apr. 01, 2018			103,500,000
Balance, beginning of period at Apr. 01, 2018	512.5		$ 0.0	1,237.2	(1.5)	(723.2)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	1.7			1.7
Restricted stock issued and related taxes (in shares)			0
Restricted stock issued and related taxes	(0.1)			(0.1)
Net income (loss)	(7.7)					(7.7)
Other comprehensive income (loss), net of tax	0.1				0.1
Balance, end of period (in shares) at Jul. 01, 2018			103,500,000
Balance, end of period at Jul. 01, 2018	506.5		$ 0.0	1,238.8	(1.4)	(730.9)
Balance, beginning of period at Dec. 30, 2018	$ 0.0	0.0
Balance, end of period at Mar. 31, 2019		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	0.0				3.1
Other comprehensive income (loss), net of tax	0.0				0.0
Changes in noncontrolling interest	0.0	15.0
Balance, end of period (in shares) at Mar. 31, 2019			105,900,000
Balance, end of period at Mar. 31, 2019	552.9		$ 0.0	1,275.0	(0.7)	(721.4)
Balance, beginning of period at Dec. 30, 2018	0.0	0.0
Balance, end of period at Jun. 30, 2019	$ 15.4	15.4
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
Net income (loss)	7.0
Other comprehensive income (loss), net of tax	$ (0.1)
Balance, end of period (in shares) at Jun. 30, 2019	105,914,292		105,900,000
Balance, end of period at Jun. 30, 2019	$ 559.5		$ 0.0	1,277.8	(0.8)	(717.5)
Balance, beginning of period at Mar. 31, 2019		15.0
Balance, end of period at Jun. 30, 2019	15.4	15.4
Balance, beginning of period (in shares) at Mar. 31, 2019			105,900,000
Balance, beginning of period at Mar. 31, 2019	552.9		$ 0.0	1,275.0	(0.7)	(721.4)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	2.8			2.8
Net income (loss)	3.9	$ 0.4				3.9
Other comprehensive income (loss), net of tax	$ (0.1)				(0.1)
Balance, end of period (in shares) at Jun. 30, 2019	105,914,292		105,900,000
Balance, end of period at Jun. 30, 2019	$ 559.5		$ 0.0	$ 1,277.8	$ (0.8)	$ (717.5)