Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Oct. 16, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Common stock, par value (in USD per share)	$ 1.25		$ 1.25
Common stock, authorized (in shares)	220,000,000	220,000,000	120,000,000
Common stock, outstanding (in shares)	100,591,940		92,394,155	85,506,218	79,549,080
South Jersey Gas Company
Common stock, par value (in USD per share)	$ 2.50		$ 2.50
Common stock, authorized (in shares)	4,000,000		4,000,000
Common stock, outstanding (in shares)	2,339,139		2,339,139