Shareholders' Equity - Schedule of Common Stock Outstanding (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Increase (Decrease) in Stockholders' Equity
Beginning balance	461,004,742	404,729,616
Additional shares subject to forward sale (in shares)	68,000,000	0
Ending balance	536,669,722	461,004,742
Stock Incentive Plan
Increase (Decrease) in Stockholders' Equity
Stock issued during period (in shares)	164,980	167,493
Performance-Based Stock Incentive Plan
Increase (Decrease) in Stockholders' Equity
Options issued during the period (in shares)	239,437	157,512
Follow-On Offerings
Increase (Decrease) in Stockholders' Equity
Stock issued during period (in shares)	0	50,000,000
Additional shares subject to forward sale (in shares)	26,900,000
ATM Stock Offering Program
Increase (Decrease) in Stockholders' Equity
Stock issued during period (in shares)	7,500,000	6,107,633