Segment Information (Company's Segment Information, Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total assets	$ 12,928,986	$ 9,361,985
Other [Member]
Segment Reporting Information [Line Items]
Total assets	204,372	2,092,581
Regulated [Member] | Water [Member]
Segment Reporting Information [Line Items]
Total assets	7,362,550	$ 7,269,404
Regulated [Member] | Natural Gas [Member]
Segment Reporting Information [Line Items]
Total assets	$ 5,362,064