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Long-Term Debt And Loans Payable (Narrative) (Details) - USD ($)				1 Months Ended				12 Months Ended
	May 18, 2019	Apr. 26, 2019	Apr. 24, 2019	Dec. 31, 2019	Sep. 30, 2019	May 31, 2019	Jul. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 30, 2018	Oct. 31, 2018	Oct. 22, 2018	Jun. 30, 2018
Debt Instrument [Line Items]
Aqua Pennsylvania's retainied earnings including minority interest				$ 1,210,072,000				$ 1,210,072,000	$ 1,174,245,000
Restricted assets				2,450,381,000				2,450,381,000
Total net assets				3,880,860,000				$ 3,880,860,000
Average borrowings cost percentage								3.12%	2.68%
Maximum amount outstanding at the end of any one month								$ 0	$ 0
Average borrowing amount								0	0
Interest income								25,406,000	152,000	$ 202,000
Interest cost								125,383,000	99,054,000	88,543,000
Capitalized amount								4,231,000	3,332,000	$ 3,578,000
Debt redeemed	$ 313,500,000	$ 313,500,000	$ 313,500,000
Make whole payment	25,237,000					$ 25,237,000		25,237,000
Debt issuance costs	18,528,000
Regulatory assets	$ 6,709,000			878,132,000				878,132,000	$ 788,076,000
interest rate swaps settled			$ 83,520,000					83,520,000
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value												$ 850,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Letters of credit capacity available				32,876,000				32,876,000
Peoples [Member]
Debt Instrument [Line Items]
Total purchase price		436,000,000
Aqua Pennsylvanias [Member]
Debt Instrument [Line Items]
Aqua Pennsylvania retained earning excluding minority interest				1,591,800,000				1,591,800,000
Aqua Pennsylvania's retainied earnings including minority interest				1,611,800,000				1,611,800,000
Restricted net assets				1,332,017,000				1,332,017,000
Total net assets				1,775,110,000				$ 1,775,110,000
Average borrowings cost percentage								3.12%	2.68%
Commitment fee percentage								0.05%
Maximum amount outstanding at the end of any one month								$ 39,930,000	$ 45,000,000
Average borrowing amount								21,871,000	$ 22,056,000
Other Subsidiaries [Member]
Debt Instrument [Line Items]
Aqua Pennsylvania retained earning excluding minority interest				221,466,000				221,466,000
Aqua Pennsylvania's retainied earnings including minority interest				270,192,000				270,192,000
Swing-Line Commitment [Member]
Debt Instrument [Line Items]
Letters of credit capacity available				50,000,000				50,000,000
Available capacity borrowed				0				$ 0
Average borrowings cost percentage								3.55%	2.92%
Average borrowing amount								$ 102,973,000	$ 207,277,000
Unsecured Revolving Credit Facility With Four Banks [Member]
Debt Instrument [Line Items]
Term of debt								364 days
Available capacity borrowed				25,724,000				$ 25,724,000	15,449,000
Funds borrowed under credit facility											$ 100,000,000
Unsecured Revolving Credit Facility Maturity Year 2017 [Member]
Debt Instrument [Line Items]
Sublimit for daily demand loans								25,000,000
Unsecured Revolving Credit Facility [Member] \| Letter of Credit [Member]
Debt Instrument [Line Items]
Debt instrument, issued				550,000				$ 550,000
Term of debt								5 years
Additional facility				150,000,000				$ 150,000,000
Unsecured Revolving Credit Facility, Replaced [Member] \| Letter of Credit [Member]
Debt Instrument [Line Items]
Debt instrument, issued				500,000				$ 500,000
Term of debt								5 years
Short-Term Line Of Credit [Member]
Debt Instrument [Line Items]
Short-term lines of credit				35,500,000				$ 35,500,000	35,500,000
Funds borrowed under credit facility				$ 0				0	$ 0
Senior Unsecured Bridge Loan [Member]
Debt Instrument [Line Items]
Debt instrument, issued													$ 5,100,000,000
Repayments of Debt								$ 4,350,000,000
Senior Notes [Member] \| Peoples [Member]
Debt Instrument [Line Items]
Debt instrument, issued		900,000,000
Payments of Debt Issuance Costs		7,931,000
Senior Notes Maturity Year 2029 [Member] \| Peoples [Member]
Debt Instrument [Line Items]
Debt instrument, issued		$ 400,000,000
Interest rate		3.566%
Debt maturity		2029
Senior Notes Maturity Year 2049 [Member] \| Peoples [Member]
Debt Instrument [Line Items]
Debt instrument, issued		$ 500,000,000
Interest rate		4.276%
Debt maturity		2049
Long-Term Debt [Member]
Debt Instrument [Line Items]
Weighted average cost of long-term debt				4.09%				4.09%	4.23%
Fixed Rate Long Term Debt [Member]
Debt Instrument [Line Items]
Weighted average cost of fixed rate long-term debt				4.09%				4.09%	4.31%
Minimum [Member]
Debt Instrument [Line Items]
Redemption percentage	3.57%					3.57%
Original maturity	2019
Maximum [Member]
Debt Instrument [Line Items]
Redemption percentage	5.83%					5.83%
Original maturity	2037
Maximum [Member] \| Unsecured Revolving Credit Facility [Member] \| Letter of Credit [Member]
Debt Instrument [Line Items]
Additional facility				$ 300,000,000				$ 300,000,000
Aqua Pennsylvania, Inc [Member]
Debt Instrument [Line Items]
Debt instrument, issued											125,000
Aqua Pennsylvania, Inc [Member] \| Tax-Exempt Bond [Member] \| Bonds [Member]
Debt Instrument [Line Items]
Debt redeemed							$ 49,660,000
Redemption percentage							5.25%
Aqua Pennsylvania, Inc [Member] \| Tax-Exempt Bond [Member] \| Bonds Due 2042 [Member]
Debt Instrument [Line Items]
Original maturity								2042
Aqua Pennsylvania, Inc [Member] \| Tax-Exempt Bond [Member] \| Bonds Due 2043 [Member]
Debt Instrument [Line Items]
Original maturity								2043
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt instrument, issued				$ 125,000,000	$ 175,000,000	$ 125,000,000		$ 125,000,000						$ 100,000,000
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2047 [Member]
Debt Instrument [Line Items]
Debt instrument, issued											65,000
Interest rate				4.44%				4.44%
Debt maturity								2047
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2052 [Member]
Debt Instrument [Line Items]
Debt instrument, issued											30,000
Interest rate				4.49%				4.49%
Debt maturity								2052
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2053 [Member]
Debt Instrument [Line Items]
Debt instrument, issued											$ 30,000
Interest rate				4.51%				4.51%
Debt maturity								2053
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2048 [Member]
Debt Instrument [Line Items]
Debt instrument, issued				$ 65,000,000				$ 65,000,000
Interest rate				4.09%				4.09%
Debt maturity								2048
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2045 [Member]
Debt Instrument [Line Items]
Debt instrument, issued				$ 10,000,000				$ 10,000,000
Interest rate				4.04%				4.04%
Debt maturity								2045
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2052 [Member]
Debt Instrument [Line Items]
Debt instrument, issued				$ 75,000,000				$ 75,000,000
Interest rate				3.39%				3.39%
Debt maturity				2052
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2053 [Member]
Debt Instrument [Line Items]
Debt instrument, issued				$ 50,000,000				$ 50,000,000
Interest rate				3.41%				3.41%
Debt maturity				2053
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2042 [Member]
Debt Instrument [Line Items]
Debt instrument, issued				$ 25,000,000				$ 25,000,000
Interest rate				3.99%				3.99%
Debt maturity								2042
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2049 [Member]
Debt Instrument [Line Items]
Debt instrument, issued						$ 75,000,000
Interest rate						4.02%
Debt maturity						2049
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2054 [Member]
Debt Instrument [Line Items]
Debt instrument, issued						$ 25,000,000
Interest rate						4.07%
Debt maturity						2054
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2059 [Member]
Debt Instrument [Line Items]
Debt instrument, issued						$ 25,000,000
Interest rate						4.12%
Debt maturity						2059
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2054 [Member]
Debt Instrument [Line Items]
Debt instrument, issued					$ 50,000,000
Interest rate					4.09%
Debt maturity					2054
Aqua Pennsylvania, Inc [Member] \| First Mortgage Bonds Maturity Year 2058 [Member]
Debt Instrument [Line Items]
Debt instrument, issued					$ 75,000,000
Interest rate					4.13%
Debt maturity					2058
Aqua Pennsylvania, Inc [Member] \| Senior Unsecured Notes Maturity Year 2059 [Member]
Debt Instrument [Line Items]
Debt instrument, issued					$ 50,000,000
Interest rate					4.14%
Debt maturity					2059