Supplemental Information (Earnings Per Share) (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share Reconciliation [Abstract]
Weighted-average Common Shares Outstanding – Basic	254,400,000	246,400,000
Assumed settlement of performance share units and restricted stock units	1,500,000	1,100,000
Dilutive effect of forward sale agreement	0	600,000
Weighted-average Common Shares Outstanding – Diluted	255,900,000	248,100,000
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	0	0