Stockholders' Equity - Summary of Changes in Stockholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2016	Sep. 27, 2015	Sep. 25, 2016	Sep. 27, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders’ equity at beginning of period			$ 254.2	$ 224.3
Comprehensive loss:
Net income (loss)	$ (23.6)	$ 55.1	(56.2)	23.8
Change in cumulative translation adjustment	(0.1)	0.1	(0.2)	0.2
Comprehensive income (loss)	(23.7)	55.2	(56.4)	24.0
Stock-based compensation			4.2	5.8
Issuance of common stock for employee stock purchase plan			2.6	4.0
Restricted stock units traded for taxes			(0.5)	(0.5)
Stockholders’ equity at end of period	$ 204.1	$ 257.6	$ 204.1	$ 257.6