Equity and Capital - Common Stock (Details) $ / shares in Units, $ in Thousands			1 Months Ended			3 Months Ended		9 Months Ended
	Nov. 03, 2021 $ / shares	Feb. 03, 2021 USD ($)	Sep. 30, 2021 USD ($) Agreement $ / shares shares	Jun. 30, 2021 $ / shares shares	May 31, 2021 $ / shares shares	Sep. 30, 2021 $ / shares shares	Sep. 30, 2020 $ / shares	Sep. 30, 2021 USD ($) $ / shares shares	Sep. 30, 2020 USD ($) $ / shares
Class of Stock [Line Items]
Common stock dividend declared, per share | $ / shares						$ 0.595	$ 0.595	$ 1.785	$ 1.785
Net proceeds from common stock issuance								$ 82,510	$ 125,608
Common stock remaining available for Issuance | shares			350,400,000			350,400,000		350,400,000
Stock Repurchase Program, Authorized Amount		$ 250,000
Stock Repurchase Program Expiration Date		Feb. 03, 2023
Subsequent Event [Member]
Class of Stock [Line Items]
Common stock dividend declared, per share | $ / shares	$ 0.625
Common stock, dividends payable date	Jan. 05, 2022
Common stock, dividends record date	Dec. 16, 2021
Common stock, dividends declared date	Nov. 03, 2021
Common Stock [Member] | AOCI Attributable to Parent
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value								$ 0
ATM Equity Offering Program [Member] | Forward Equity Offering [Member]
Class of Stock [Line Items]
Number of shares issuable | shares			1,332,142	2,316,760	2,316,760
Sale of stock, average offering price | $ / shares			$ 63.71	$ 64.59	$ 64.59	$ 63.71		$ 63.71
Number of forward sale agreement settled | Agreement			2
Underwriting discount and offering expense			$ 1,100
Settlement period								1 year
Proceeds from issuance of remaining shares of common stock								$ 64,000
Net proceeds from common stock issuance			$ 82,500
Maximum [Member]
Class of Stock [Line Items]
Equity Issuances, Common Shares Authorized for Issuance | shares			500			500		500