Common Stock (Details) - USD ($)	1 Months Ended		12 Months Ended
	Feb. 28, 2021	Sep. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shelf registration, shares issued (in shares)		7,000,000
Shelf registration, price per share (in dollars per share)		$ 56.50
Shelf registration, net proceeds		$ 379,410,000
Total allowable shares (in shares)			375,000,000	375,000,000
Total shares issued (in shares)			175,635,792	175,232,971
Shares of common stock (in shares)					7,000,000
Net proceeds					$ 395,500,000
Stock issuance costs		$ 16,090,000	$ 325,000	$ 2,223,000	17,521,000
Net proceeds			$ 4,053,000	$ 126,488,000	$ 542,280,000
2020 ATM Equity Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total allowable shares (in shares)			17,500,000,000
Total shares issued (in shares)			1,599,304,000
2018 ATM Equity Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total allowable shares (in shares)			12,000,000,000
Total shares issued (in shares)			11,272,034,000
ATM Equity Programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock (in shares)			30,000,000	3,119,153,000	2,344,022,000
Average price per share (net) (in dollars per share)			$ 33.65	$ 38.21	$ 53.71
Net proceeds			$ 1,009,000	$ 119,185,000	$ 125,905,000
Stock issuance costs			$ 224,000	$ 2,130,000	$ 1,431,000
DRIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares permitted for issuance (in shares)	6,000,000
Shares of common stock (in shares)			62,577,000	138,507,000	362,918,000
Net proceeds			$ 2,744,000	$ 5,092,000	$ 19,442,000