Long-Term Debt (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Apr. 03, 2021 USD ($) $ / shares	Apr. 04, 2020 USD ($)	Dec. 31, 2020 USD ($)
Debt Instruments [Abstract]
Credit facility	$ 0		$ 0
Deferred financing costs	(12,131)		(11,512)
Long-term debt	453,213		394,886
Less current portion	0		0
Long-term debt, less current portion	453,213		394,886
Interest expense [Abstract]
Contractual coupon interest		$ 3,419
Non-cash amortization of debt discount	0	3,637
Other non-cash interest expense (income)		454
Total interest expense related to the debentures		7,510
Purchase price of extinguished debt	300	19,849
Loss on extinguishment of debt, including the write-off of portion of unamortized debt issuance costs	0	(2,920)
Convertible Senior Notes, Due 2025 [Member]
Debt Instruments [Abstract]
Convertible debt	$ 465,344		406,268
Issuance date	Jun. 12, 2018
Debt maturity date	Jun. 15, 2025
Cash coupon rate	2.25%
Nonconvertible debt borrowing rate at issuance	5.50%
Effective conversion rate	31.8965
Effective conversion price (in dollars per share) | $ / shares	$ 31.35
130% of the conversion price (in dollars per share) | $ / shares	$ 40.76
Debt instrument percentage of conversion price	130.00%
Debt instrument percentage of sales price of common stock	98.00%
Maximum threshold of quarterly cash dividends per share of common stock for not adjusting conversion rate of convertible notes | $ / shares	$ 0.085
Liability and equity components of convertible debentures [Abstract]
Principal amount of debt	$ 465,344
Interest expense [Abstract]
Contractual coupon interest	2,618	3,375
Non-cash amortization of debt discount	0	3,617
Other non-cash interest expense (income)	433	454
Total interest expense related to the debentures	3,051	7,446
Convertible Senior Debentures, Due 2040 [Member]
Debt Instruments [Abstract]
Convertible debt	$ 0		130
Convertible Senior Debentures [Member]
Interest expense [Abstract]
Contractual coupon interest		44
Non-cash amortization of debt discount		20
Other non-cash interest expense (income)		0
Total interest expense related to the debentures		$ 64
Convertible Debt [Member]
Liability and equity components of convertible debentures [Abstract]
Principal amount of debt			465,644
Unamortized discount			(59,246)
Carrying value of liability component			406,398
Equity component - net carrying value			66,248
Convertible Debt [Member] | Convertible Senior Notes, Due 2025 [Member]
Liability and equity components of convertible debentures [Abstract]
Principal amount of debt			465,344
Unamortized discount			(59,076)
Carrying value of liability component			406,268
Equity component - net carrying value			66,127
Convertible Debt [Member] | Convertible Senior Debentures, Due 2040 [Member]
Liability and equity components of convertible debentures [Abstract]
Principal amount of debt			300
Unamortized discount			(170)
Carrying value of liability component			130
Equity component - net carrying value			$ 121