Shareholders' Equity - Forward Sales Agreement (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Class of Stock [Line Items]
Shares Available (in shares) | shares	2,452,177
Net Proceeds Available | $	$ 246,834
Forward Price (dollars per share) | $ / shares	$ 100.66
Forward Sales Equity Agreement, Maturing Quarter ended June 30, 2021
Class of Stock [Line Items]
Shares Available (in shares) | shares	1,060,660
Net Proceeds Available | $	$ 107,255
Forward Price (dollars per share) | $ / shares	$ 101.12
Forward Sales Equity Agreement, Maturing Quarter ended September 30, 2021
Class of Stock [Line Items]
Shares Available (in shares) | shares	1,391,517
Net Proceeds Available | $	$ 139,579
Forward Price (dollars per share) | $ / shares	$ 100.31