Equity and Capital - Equity Distribution Agreement (Details) - Sales Agreement - USD ($) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Class of Stock [Line Items]
Common stock issued in public offering (shares)	0.5	4.6
Average price per share	$ 161.57	$ 142.39
Amount of shares reserved for future issuance	$ 672.2
Maximum
Class of Stock [Line Items]
Aggregate offering price of the distribution agreement maximum	$ 1,000.0