Pension Plans And Other Postretirement Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2016

Pension and Other Post Retirement Benefit Plans

	Pension Benefits						Other Post- retirement Benefits
	2016			2015			2016			2015
Change in benefit obligation:
Benefit obligation as of beginning of year	$	613,503		$	634,674		$	138,795		$	127,989
Service cost	18,302			19,791			3,205			2,925
Interest cost	27,544			26,117			6,110			5,158
Actuarial (gain)/loss	39,997			(35,790		)	(3,648		)	12,668
Plan change	—			(228		)	—			(1,000		)
Cumulative adjustment to reclassify liability	—			—			(1,042		)	(1,521		)
Benefits paid	(32,874		)	(31,061		)	(6,967		)	(7,424		)
Benefit obligation as of end of year	$	666,472		$	613,503		$	136,453		$	138,795
Change in plan assets:
Fair value of plan assets as of beginning of year	$	517,234		$	539,311		$	30,868		$	31,312
Actual return on plan assets	43,212			(4,305		)	2,497			(444		)
Employer contributions	12,000			12,000			—			—
Benefits paid	(31,532		)	(29,772		)	—			—
Fair value of plan assets as of end of year	$	540,914		$	517,234		$	33,365		$	30,868
Funded status	$	(125,558	)	$	(96,269	)	$	(103,088	)	$	(107,927	)
Unrecognized net actuarial loss	178,783			162,961			81,979			92,433
Unrecognized prior service cost	23			25			(8,981		)	(10,180		)
Prepaid (accrued) benefit cost	53,248			66,717			(30,090		)	(25,674		)
Additional liability	(178,806		)	(162,986		)	(72,998		)	(82,253		)
Accrued benefit liability	$	(125,558	)	$	(96,269	)	$	(103,088	)	$	(107,927	)
Accumulated pension benefit obligation	$	583,498		$	542,209		—			—
Accumulated postretirement benefit obligation:
For retirees							$	60,670		$	65,652
For fully eligible employees							$	34,429		$	34,498
For other participants							$	41,354		$	38,645

	Pension Benefits						Other Post- retirement Benefits
	2016			2015			2016			2015
Included in accumulated other comprehensive loss (income) (net of tax):
Unrecognized prior service cost	$	15		$	16		$	(5,854	)	$	(6,617	)
Unrecognized net actuarial loss	116,209			105,925			53,303			60,081
Total	116,224			105,941			47,449			53,464
Less regulatory asset	(108,903		)	(99,414		)	(47,202		)	(53,341		)
Accumulated other comprehensive loss for unfunded benefit obligation for pensions and other postretirement benefit plans	$	7,321		$	6,527		$	247		$	123

	Pension Benefits				Other Post- retirement Benefits
	2016		2015		2016		2015
Weighted-average assumptions as of December 31:
Discount rate for benefit obligation	4.26	%	4.57	%	4.23	%	4.57	%
Discount rate for annual expense	4.57	%	4.21	%	4.57	%	4.16	%
Expected long-term return on plan assets	5.40	%	5.30	%	6.03	%	6.36	%
Rate of compensation increase	4.78	%	4.87	%
Medical cost trend pre-age 65 – initial					7.00	%	7.00	%
Medical cost trend pre-age 65 – ultimate					5.00	%	5.00	%
Ultimate medical cost trend year pre-age 65					2023		2022
Medical cost trend post-age 65 – initial					7.00	%	7.00	%
Medical cost trend post-age 65 – ultimate					5.00	%	5.00	%
Ultimate medical cost trend year post-age 65					2024		2023

Components of Net Periodic Benefit Cost

	Pension Benefits									Other Post-retirement Benefits
	2016			2015			2014			2016			2015			2014
Components of net periodic benefit cost:
Service cost	$	18,302		$	19,791		$	15,757		$	3,205		$	2,925		$	1,844
Interest cost	27,544			26,117			26,224			6,110			5,158			5,226
Expected return on plan assets	(27,547		)	(28,299		)	(32,131		)	(1,861		)	(1,991		)	(1,903		)
Amortization of prior service cost	2			2			22			(1,208		)	(1,199		)	(1,116		)
Net loss recognition	8,511			9,451			4,731			5,728			5,095			4,289
Net periodic benefit cost	$	26,812		$	27,062		$	14,603		$	11,974		$	9,988		$	8,340

Schedule of Allocation of Plan Assets

	2016		2015
Equity securities	37	%	27	%
Debt securities	45	%	58	%
Real estate	8	%	6	%
Absolute return	10	%	9	%

Employer Matching Contributions

Employer matching contributions were as follows for the years ended December 31 (dollars in thousands):

	2016		2015		2014
Employer 401(k) matching contributions	$	8,710	$	8,011	$	6,862

Deferred Compensation Liabilities Included in other Non-Current Liabilities and Deferred Credits

There were deferred compensation assets included in other property and investments-net and corresponding deferred compensation liabilities included in other non-current liabilities and deferred credits on the Consolidated Balance Sheets of the following amounts as of December 31 (dollars in thousands):

	2016		2015
Deferred compensation assets and liabilities	$	7,679	$	8,093

Other Post-Retirement Benefits [Member]

Schedule of Expected Benefit Payments

The Company expects that benefit payments under other postretirement benefit plans will total (dollars in thousands):

	2017		2018		2019		2020		2021		Total 2022-2026
Expected benefit payments	$	6,991	$	7,302	$	7,580	$	6,479	$	6,675	$	34,704

Schedule of Allocation of Plan Assets

The following table discloses by level within the fair value hierarchy (see Note 16 for a description of the fair value hierarchy) of other postretirement plan assets measured and reported as of December 31, 2016 at fair value (dollars in thousands):

	Level 1		Level 2		Level 3		Total
Cash equivalents	$	—	$	6	$	—	$	6
Mutual funds:
Balanced index fund (1)	33,359		—		—		33,359
Total	$	33,359	$	6	$	—	$	33,365

(1) The balanced index fund is a single mutual fund that includes a percentage of U.S. equity securities, fixed income securities and International securities.

The following table discloses by level within the fair value hierarchy (see Note 16 for a description of the fair value hierarchy) of other postretirement plan assets measured and reported as of December 31, 2015 at fair value (dollars in thousands):

	Level 1		Level 2		Level 3		Total
Cash equivalents	$	—	$	9	$	—	$	9
Mutual funds:
Fixed income securities	12,000		—		—		12,000
U.S. equity securities	13,224		—		—		13,224
International equity securities	5,635		—		—		5,635
Total	$	30,859	$	9	$	—	$	30,868

Pension Plan And SERP [Member]

Schedule of Expected Benefit Payments

The Company expects that benefit payments under the pension plan and the SERP will total (dollars in thousands):

	2017		2018		2019		2020		2021		Total 2022-2026
Expected benefit payments	$	30,971	$	32,014	$	33,047	$	34,545	$	35,892	$	196,322

The Company expects that benefit payments under the pension plan and the SERP will total (dollars in thousands):

	2017		2018		2019		2020		2021		Total 2022-2026
Expected benefit payments	$	30,971	$	32,014	$	33,047	$	34,545	$	35,892	$	196,322

Schedule of Allocation of Plan Assets

The following table discloses by level within the fair value hierarchy (see Note 16 for a description of the fair value hierarchy) of the pension plan’s assets measured and reported as of December 31, 2016 at fair value (dollars in thousands):

	Level 1		Level 2		Level 3		Total
Cash equivalents	$	—	$	10,179	$	—	$	10,179
Fixed income securities:
U.S. government issues	—		30,919		—		30,919
Corporate issues	—		193,563		—		193,563
International issues	—		34,145		—		34,145
Municipal issues	—		18,888		—		18,888
Mutual funds:
U.S. equity securities	120,856		—		—		120,856
International equity securities	30,025		—		—		30,025
Absolute return (1)	6,622		—		—		6,622
Plan assets measured at NAV (not subject to hierarchy disclosure)
Common/collective trusts:
Real estate	—		—		—		19,779
International equity securities	—		—		—		29,140
Partnership/closely held investments:
Absolute return (1)	—		—		—		39,077
Private equity funds (2)	—		—		—		72
Real estate	—		—		—		7,649
Total	$	157,503	$	287,694	$	—	$	540,914

The following table discloses by level within the fair value hierarchy (see Note 16 for a description of the fair value hierarchy) of the pension plan’s assets measured and reported as of December 31, 2015 at fair value (dollars in thousands):

	Level 1		Level 2		Level 3		Total
Cash equivalents	$	86	$	10,641	$	—	$	10,727
Fixed income securities:
U.S. government issues	—		47,845		—		47,845
Corporate issues	—		187,308		—		187,308
International issues	—		34,458		—		34,458
Municipal issues	—		22,416		—		22,416
Mutual funds:
U.S. equity securities	87,678		—		—		87,678
International equity securities	40,343		—		—		40,343
Absolute return (1)	13,996		—		—		13,996
Plan assets measured at NAV (not subject to hierarchy disclosure)
Common/collective trusts:
Real estate	—		—		—		24,147
Partnership/closely held investments:
Absolute return (1)	—		—		—		38,302
Private equity funds (2)	—		—		—		73
Real estate	—		—		—		9,941
Total	$	142,103	$	302,668	$	—	$	517,234

(1) This category invests in multiple strategies to diversify risk and reduce volatility. The strategies include: (a) event driven, relative value, convertible, and fixed income arbitrage, (b) distressed investments, (c) long/short equity and fixed income, and (d) market neutral strategies.

(2) This category includes private equity funds that invest primarily in U.S. companies.