Stock-Based Compensation (Activity Pertaining to Nonemployee Director Stock Award Plan) (Details) - Directors Plan - $ / shares		8 Months Ended	12 Months Ended
	Sep. 01, 2020	Aug. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, beginning balance	28,000	42,000	66,500
Weighted average price, beginning balance	$ 52.24	$ 48.56	$ 44.42
Number of shares, granted		0	0
Weighted average price, granted		$ 0	$ 0
Number of shares, exercised		0	0
Weighted average price, exercised		$ 0	$ 0
Number of shares, forfeited		(14,000)	(24,500)
Weighted average price, forfeited		$ 41.21	$ 37.31
Number of shares, cancelled	28,000
Weighted average price, cancellation	$ 52.24
Number of shares, ending balance	0	28,000	42,000
Weighted average price, ending balance	$ 0	$ 52.24	$ 48.56