Capitalization (Details)					1 Months Ended		3 Months Ended		9 Months Ended
	May 18, 2019 USD ($)	Apr. 26, 2019 USD ($)	Apr. 23, 2019 USD ($) $ / shares	Mar. 29, 2019 USD ($) item $ / shares shares	Sep. 30, 2019 USD ($) $ / shares	May 31, 2019 USD ($)	Sep. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2019 USD ($)	Sep. 30, 2019 USD ($) $ / shares	Sep. 30, 2018 USD ($)	Dec. 31, 2018 $ / shares
Debt Instrument [Line Items]
Private Placement | shares				21,661,095
Proceeds from private placement				$ 750,000,000
Common stock, par value | $ / shares				$ 0.50	$ 0.50		$ 0.50		$ 0.50		$ 0.50
Issuance expense				$ 21,560,000
Private placement discount				4.50%
Trading days | item				20
Diligence expenses				$ 4,000,000
Issuance of common stock under dividend reinvestment plan									$ 4,819,000	$ 1,101,000
Private placement price | $ / shares				$ 34.62
Repayments of long-term debt									888,951,000	151,571,000
Debt redeemed									888,951,000	151,571,000
Pre-payment penalty									25,237,000
Long-Term Due 2019 [Member]
Debt Instrument [Line Items]
Maturity Year	2019
Redemption percentage	3.57%
Long-Term Due 2037 [Member]
Debt Instrument [Line Items]
Maturity Year	2037
Redemption percentage	5.83%
Notes Ranging 2019-2037 [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	$ 313,500,000							$ 18,920,000
Long-term debt					$ 6,317,000		$ 6,317,000		$ 6,317,000
Debt redeemed	313,500,000							$ 18,920,000
Pre-payment penalty	$ 25,237,000
Senior Notes [Member]
Debt Instrument [Line Items]
Redemption percentage									101.00%
Aqua Pennsylvania, Inc [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Face Amount						$ 125,000,000
Aqua Pennsylvania, Inc [Member] | First Mortgage Bonds Due In 2049 [Member]
Debt Instrument [Line Items]
Face Amount						$ 75,000,000
Maturity Year						2049
Interest Rate						4.02%
Aqua Pennsylvania, Inc [Member] | First Mortgage Bonds Due In 2054 [Member]
Debt Instrument [Line Items]
Face Amount						$ 25,000,000
Maturity Year						2054
Interest Rate						4.07%
Aqua Pennsylvania, Inc [Member] | First Mortgage Bonds Due In 2059 [Member]
Debt Instrument [Line Items]
Face Amount						$ 25,000,000
Maturity Year						2059
Interest Rate						4.12%
Aqua Pennsylvania, Inc [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Face Amount					175,000,000		175,000,000		$ 175,000,000
Aqua Pennsylvania, Inc [Member] | First Mortgage Bonds Due In 2054 [Member]
Debt Instrument [Line Items]
Face Amount					$ 50,000,000		$ 50,000,000		$ 50,000,000
Maturity Year					2054
Interest Rate					4.09%		4.09%		4.09%
Aqua Pennsylvania, Inc [Member] | First Mortgage Bonds Due In 2058 [Member]
Debt Instrument [Line Items]
Face Amount					$ 75,000,000		$ 75,000,000		$ 75,000,000
Maturity Year					2058
Interest Rate					4.13%		4.13%		4.13%
Aqua Pennsylvania, Inc [Member] | First Mortgage Bonds Due In 2059 [Member]
Debt Instrument [Line Items]
Face Amount					$ 50,000,000		$ 50,000,000		$ 50,000,000
Maturity Year					2059
Interest Rate					4.14%		4.14%		4.14%
LDC Funding LLC [Member]
Debt Instrument [Line Items]
Issuance expense			$ 30,651,000
Private placement, per share | $ / shares			$ 50
Issuance of common stock under dividend reinvestment plan			$ 1,293,750,000
Private placement price | $ / shares				$ 34.62
Proceeds from tangible equity units			690,000,000
Debt issuance expense			$ 16,358,000
Share price | $ / shares			$ 34.62
Initial principal amount			$ 119,081,000
Initial principal amount per share | $ / shares			$ 8.62909
Cash installment | $ / shares			$ 0.75000
Cash installment rate			6.00%
Additional paid in capital			$ 570,919,000
insurance			$ 13,530,000
Interest Rate			3.00%
Amortization of notes			$ 119,081,000
Amortization of issuance costs			$ 2,828,000
Purchase contracts settled | shares							25,000
Issuance of common stock | shares							29,484
LDC Funding LLC [Member] | July 30, 2019 [Member]
Debt Instrument [Line Items]
Cash installment | $ / shares			$ 0.80833
LDC Funding LLC [Member] | First Mortgage Bonds Due In 2029 [Member]
Debt Instrument [Line Items]
Maturity date		2029
Face Amount		$ 400,000,000
Interest Rate		3.566%
LDC Funding LLC [Member] | First Mortgage Bonds Due In 2049 [Member]
Debt Instrument [Line Items]
Maturity date		2049
Face Amount		$ 500,000,000
Interest Rate		4.276%
LDC Funding LLC [Member] | Long-Term [Member]
Debt Instrument [Line Items]
Debt issuance expense		$ 7,931,000
Face Amount		$ 900,000,000
LDC Funding LLC [Member] | Minimum [Member]
Debt Instrument [Line Items]
Conversion to shares | $ / shares			1.1790
LDC Funding LLC [Member] | Maximum [Member]
Debt Instrument [Line Items]
Conversion to shares | $ / shares			$ 1.4442