Distributions Paid and Payable - Distributions to Common Stockholders (Details) - $ / shares	1 Months Ended																			9 Months Ended
	Oct. 31, 2020	Sep. 30, 2020	Aug. 31, 2020	Jul. 31, 2020	Jun. 30, 2020	May 31, 2020	Apr. 30, 2020	Mar. 31, 2020	Feb. 29, 2020	Jan. 31, 2020	Sep. 30, 2019	Aug. 31, 2019	Jul. 31, 2019	Jun. 30, 2019	May 31, 2019	Apr. 30, 2019	Mar. 31, 2019	Feb. 28, 2019	Jan. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Distributions Paid and Payable
Distributions paid per common share (in dollars per share)		$ 0.2335	$ 0.2335	$ 0.2335	$ 0.2330	$ 0.2330	$ 0.2330	$ 0.2325	$ 0.2325	$ 0.2275	$ 0.2265	$ 0.2265	$ 0.2265	$ 0.2260	$ 0.2260	$ 0.2260	$ 0.2255	$ 0.2255	$ 0.2210	$ 2.0920	$ 2.0295
Distributions payable (in dollars per share)		$ 0.2340																		$ 0.2340
Subsequent event
Distributions Paid and Payable
Distributions paid per common share (in dollars per share)	$ 0.2340