Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Change in projected benefit obligation and fair value of plan assets

	(Thousands of Dollars)
	Pension Plan						Other Benefits Plan
	December 31,
	2016			2015			2016			2015
Change in Projected Benefit Obligation:
Beginning Balance	$	72,542		$	75,043		$	46,249		$	49,578
Service Cost		2,308			2,558			1,099			1,373
Interest Cost		3,046			2,894			1,952			1,921
Actuarial (Gain) Loss		2,810			(5,915	)		141			(6,062	)
Benefits Paid		(2,105	)		(2,038	)		(553	)		(561	)
Ending Balance	$	78,601		$	72,542		$	48,888		$	46,249

	(Thousands of Dollars)
	Pension Plan						Other Benefits Plan
	December 31,
	2016			2015			2016			2015
Change in Fair Value of Plan Assets:
Beginning Balance	$	52,931		$	51,623		$	29,018		$	27,535
Actual Return on Plan Assets		4,909			11			1,591			350
Employer Contributions		3,635			3,335			1,551			1,694
Benefits Paid		(2,105	)		(2,038	)		(553	)		(561	)
Ending Balance	$	59,370		$	52,931		$	31,607		$	29,018
Funded Status	$	(19,231	)	$	(19,611	)	$	(17,281	)	$	(17,231	)

Amounts recognized in balance sheet

	(Thousands of Dollars)
	Pension Plan				Other Benefits Plan
	December 31,
	2016		2015		2016		2015
Amounts Recognized in the Consolidated Balance Sheets consist of :
Current Liability		373		327		—		—
Noncurrent Liability		18,858		19,284		17,281		17,231
Net Liability Recognized	$	19,231	$	19,611	$	17,281	$	17,231

Components of net benefit cost

	(Thousands of Dollars)
	Pension Plan									Other Benefits Plan
	Years Ended December 31,
	2016			2015			2014			2016			2015			2014
Components of Net Periodic Benefit Cost
Service Cost	$	2,308		$	2,558		$	1,894		$	1,099		$	1,373		$	1,032
Interest Cost		3,046			2,894			2,682			1,952			1,921			1,792
Expected Return on Plan Assets		(4,014	)		(3,919	)		(3,534	)		(2,213	)		(2,107	)		(1,937	)
Amortization of Net Actuarial Loss		1,426			1,645			416			1,773			2,261			1,413
Amortization of Prior Service Cost/(Credit)		—			—			2			(1,728	)		(1,728	)		(1,728	)
Net Periodic Benefit Cost	$	2,766		$	3,178		$	1,460		$	883		$	1,720		$	572

Amounts expected to be amortized from regulatory assets

	(Thousands of Dollars)
	Pension Plan		Other Benefits Plan
Actuarial Loss	$	1,566	$	1,781
Prior Service Credit		—		(1,728	)

Discount and compensation rates

	Pension Plan									Other Benefits Plan
	2016			2015			2014			2016			2015			2014
Weighted Average Assumptions:
Expected Return on Plan Assets		7.50	%		7.50	%		7.50	%		7.50	%		7.50	%		7.50	%
Discount Rate for:
Benefit Obligation		4.06	%		4.26	%		3.91	%		4.06	%		4.26	%		3.91	%
Benefit Cost		4.26	%		3.91	%		4.87	%		4.26	%		3.91	%		4.87	%
Compensation Increase for:
Benefit Obligation		3.00	%		3.00	%		3.00	%		3.00	%		3.00	%		3.00	%
Benefit Cost		3.00	%		3.00	%		3.00	%		3.00	%		3.00	%		3.00	%

Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates

	(Thousands of Dollars)
	1 Percentage Point
	Increase		Decrease
Effect on Current Year’s Service and Interest Cost	$	673	$	(514	)
Effect on Projected Benefit Obligation	$	8,410	$	(6,633	)

Expected benefit payments

	(Thousands of Dollars)
Year	Pension Plan		Other Benefits Plan
2017	$	2,391	$	1,030
2018		2,440		1,277
2019		2,455		1,497
2020		2,847		1,641
2021		3,046		1,851
2022-2026		22,178		11,278
Totals	$	35,357	$	18,574

Allocation of plan assets

	Pension Plan									Other Benefits Plan
Asset Category	2016			2015			Target			2016			2015			Target
Equity Securities		59.7	%		59.1	%		55	%		54.1	%		50.0	%		43	%
Debt Securities		36.6	%		37.8	%		38	%		43.3	%		47.4	%		50	%
Cash		1.0	%		1.3	%		2	%		2.6	%		2.4	%		2	%
Real Estate/Commodities		2.7	%		1.8	%		5	%		0.0	%		0.2	%		5	%
Total		100.0	%		100.0	%					100.0	%		100.0	%

Fair value of plan assets

The following tables present Middlesex’s Pension Plan assets measured and recorded at fair value within the fair value hierarchy:

	(Thousands of Dollars)
	As of December 31, 2016
	Level 1		Level 2		Level 3		Total
Mutual Funds	$	49,439	$	—	$	—	$	49,439
Money Market Funds		648		—		—		648
Common Equity Securities		9,283		—		—		9,283
Total Investments	$	59,370	$	—	$	—	$	59,370

	(Thousands of Dollars)
	As of December 31, 2015
	Level 1		Level 2		Level 3		Total
Mutual Funds	$	43,623	$	—	$	—	$	43,623
Money Market Funds		652		—		—		652
Common Equity Securities		8,656		—		—		8,656
Total Investments	$	52,931	$	—	$	—	$	52,931

The following tables present Middlesex’s Other Benefits Plan assets measured and recorded at fair value within the fair value hierarchy:

	(Thousands of Dollars)
	As of December 31, 2016
	Level 1		Level 2		Level 3		Total
Mutual Funds	$	17,096	$	—	$	—	$	17,096
Money Market Funds		826		—		—		826
Preferred Equity Securities		108		—		—		108
Agency/US/State/Municipal Debt		—		13,577		—		13,577
Total Investments	$	18,030	$	13,577	$	—	$	31,607

	(Thousands of Dollars)
	As of December 31, 2015
	Level 1		Level 2		Level 3		Total
Mutual Funds	$	14,572	$	—	$	—	$	14,572
Money Markey Funds		688		—		—		688
Preferred Equity Securities		224		—		—		224
Agency/US/State/Municipal Debt		—		13,534		—		13,534
Total Investments	$	15,484	$	13,534	$	—	$	29,018

Restricted stock plan

	Shares (thousands)			Unearned Compensation (thousands)			Weighted Average Grant Price
Balance, January 1, 2014		117		$	1,216
Granted		33			711		$	21.46
Vested		(22	)		—
Forfeited		(1	)		(10	)
Amortization of Compensation Expense		—			(434	)
Balance, December 31, 2014		127		$	1,483
Granted		33			741		$	22.65
Vested		(12	)		—
Forfeited		—			—
Amortization of Compensation Expense		—			(528	)
Balance, December 31, 2015		148		$	1,696
Granted		24			750		$	30.85
Vested		(25	)		—
Forfeited		—			—
Amortization of Compensation Expense		—			(682	)
Balance, December 31, 2016		147		$	1,764