Shareholders' Equity (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 16, 2020	Jun. 18, 2019	Mar. 26, 2019	Jun. 16, 2020	Jun. 18, 2019	Jul. 23, 2018	Aug. 23, 2016	Feb. 26, 2016
Class of Stock [Line Items]
Shares repurchased, value		$ 3,067,000	$ 4,306,000
Common Stock and Warrants
Class of Stock [Line Items]
Maximum authorized stock repurchase amount (up to)						$ 75,000,000.0	$ 50,000,000.0	$ 25,000,000.0
Remaining authorized stock repurchase amount	$ 22,300,000			$ 22,300,000
Common Stock
Class of Stock [Line Items]
Shares repurchased (in shares)		303,607			574,481
Average price per share (in dollars per share)		$ 10.05			$ 10.17
Shares repurchased, value		$ 3,100,000			$ 5,900,000
Warrants
Class of Stock [Line Items]
Shares repurchased (in shares)		6,186			846,441
Average price per share (in dollars per share)		$ 1.30			$ 1.78
Shares repurchased, value	$ 8,000			$ 1,500,000