Description of Business and Summary of Significant Accounting Policies - Cumulative effect adjustment (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Dec. 31, 2020	Dec. 26, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long-term debt		$ 193,036	$ 206,432
Deferred income taxes		33,429	48,262
Capital in excess of par		153,529	145,549
Retained earnings		$ 331,897	$ 461,884
Change in accounting principle accounting standards updated early adoption		true
ASU 2020-06 | Cumulative effect period of adoption adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long-term debt	$ 21,393
Deferred income taxes	(5,584)
Capital in excess of par	(16,511)
Retained earnings	702
ASU 2020-06 | Cumulative effect period of adoption adjusted balance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long-term debt	214,429
Deferred income taxes	27,845
Capital in excess of par	137,018
Retained earnings	$ 332,599