Earnings Per Share - Reconciliation of Basic and Diluted EPS Calculations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 26, 2020	Jun. 27, 2020	Mar. 28, 2020	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Sep. 26, 2020	Sep. 28, 2019
Earnings Per Share [Abstract]
Net income	$ 35,289	$ (43,833)	$ 9,742	$ 1,192	$ 10,257	$ 17,429	$ 1,198	$ 28,879
Weighted average shares outstanding for basic EPS (shares)	80,676			78,474			80,376	78,387
Effect of dilutive securities:
Stock options (shares)	1,694			3,024			1,818	3,074
Restricted stock (shares)	195			63			114	49
2025 Notes	1,230			0			410	0
Weighted average shares outstanding for diluted EPS	83,795			81,561			82,718	81,510
Basic EPS (in usd per share)	$ 0.44			$ 0.02			$ 0.01	$ 0.37
Diluted EPS (in usd per share)	$ 0.42			$ 0.01			$ 0.01	$ 0.35
Options and RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive options, RSUs outstanding excluded from EPS (shares)	426			315			516	289