Quarterly Results of Operations (Schedule of Quarterly Financial Information) (Parenthetical) (Details) - $ / shares		3 Months Ended
	Dec. 05, 2019	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Special dividend declared per share	$ 2.50	$ 0.70	$ 0.65	$ 0.65	$ 0.65	$ 3.15	[1]	$ 0.60	[1]	$ 0.60	[1]	$ 0.60	[1]

[1] On December 5, 2019 the Board of Directors declared a special cash dividend of $2.50 per share.