Dividends on Common Stock (Details) - USD ($)				9 Months Ended
	Sep. 24, 2019	Jun. 25, 2019	Mar. 26, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2017
Equity [Abstract]
Dividends declared on common stock (in dollars per share)	$ 0.11	$ 0.11	$ 0.11
Dividends on common stock	$ 1,866,000	$ 1,865,000	$ 1,869,000	$ 3,730,000	$ 3,042,000
Authorized repurchase amount, common stock						$ 3,000,000