REGULATORY ACCOUNTING (Tables)

12 Months Ended

Dec. 31, 2018

Regulated Operations [Abstract]

Schedule of Regulatory Assets

The components of regulatory assets were as follows:

	As of December 31,
	2018								2017
(Millions of Dollars)	Eversource		CL&P		NSTAR Electric		PSNH		Eversource		CL&P		NSTAR Electric		PSNH
Benefit Costs	$	1,914.8	$	424.7	$	544.4	$	169.6	$	2,068.8	$	469.2	$	560.7	$	212.3
Income Taxes, Net	728.6		454.4		105.9		8.3		768.9		453.8		113.2		21.7
Securitized Stranded Costs	608.4		—		—		608.4		—		—		—		—
Deferred Costs from Generation Asset Sale	—		—		—		—		516.1		—		—		516.1
Storm Restoration Costs, Net	576.0		302.6		212.9		60.5		404.8		216.7		146.6		41.5
Regulatory Tracker Mechanisms	316.0		33.2		169.1		67.3		509.9		85.3		273.0		116.4
Derivative Liabilities	356.5		356.5		—		—		367.2		362.3		—		—
Goodwill-related	348.4		—		299.1		—		365.2		—		313.6		—
Asset Retirement Obligations	89.2		32.3		42.2		3.3		101.0		30.3		39.0		17.0
Other Regulatory Assets	208.0		27.0		64.6		12.1		137.4		27.6		78.4		15.8
Total Regulatory Assets	5,145.9		1,630.7		1,438.2		929.5		5,239.3		1,645.2		1,524.5		940.8
Less:  Current Portion	514.8		125.2		241.7		67.2		741.9		200.3		333.9		130.1
Total Long-Term Regulatory Assets	$	4,631.1	$	1,505.5	$	1,196.5	$	862.3	$	4,497.4	$	1,444.9	$	1,190.6	$	810.7

Schedule of Regulatory Liabilities

The components of regulatory liabilities were as follows:

	As of December 31,
	2018								2017
(Millions of Dollars)	Eversource		CL&P		NSTAR Electric		PSNH		Eversource		CL&P		NSTAR Electric		PSNH
EDIT due to Tax Cuts and Jobs Act	$	2,883.0	$	1,031.0	$	1,103.7	$	396.4	$	2,882.0	$	1,031.6	$	1,087.9	$	405.1
Cost of Removal	521.0		39.9		307.1		22.1		502.1		23.2		293.8		37.9
Benefit Costs	91.2		—		76.9		—		132.3		—		112.6		—
Regulatory Tracker Mechanisms	309.0		89.5		163.7		48.3		136.7		34.6		77.8		5.0
AFUDC - Transmission	70.7		47.4		23.3		—		67.1		48.8		18.3		—
Revenue Subject to Refund due to Tax Cuts   and Jobs Act	24.6		—		—		12.6		—		—		—		—
Other Regulatory Liabilities	80.2		24.0		29.2		4.2		45.2		12.9		3.7		2.7
Total Regulatory Liabilities	3,979.7		1,231.8		1,703.9		483.6		3,765.4		1,151.1		1,594.1		450.7
Less:  Current Portion	370.2		109.6		190.6		55.5		128.1		39.0		79.6		6.3
Total Long-Term Regulatory Liabilities	$	3,609.5	$	1,122.2	$	1,513.3	$	428.1	$	3,637.3	$	1,112.1	$	1,514.5	$	444.4