Dividends (Distributions) - Additional Information (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Payments Of Dividends [Abstract]
Common stock distribution per share	$ 0.60	[1]	$ 0.97	[2]	$ 2.40

[1] Pursuant to Internal Revenue Code Section 857(b)(9), if you were a stockholder of record as of December 15, 2020, your dividend payment of $0.1500 per share received in January 2021 was reported on Form 1099-DIV for the 2020 taxable year for federal income tax purposes.

[2] Pursuant to Internal Revenue Code Section 857(b)(9), if you were a stockholder of record as of December 31, 2019, your dividend payment of $0.2200 per share received in January 2020 was reported on Form 1099-DIV for the 2019 taxable year for federal income tax purposes.