Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2017

Schedule of reconciliation of the changes in the benefit obligations

The following tables provide a reconciliation of the changes in the benefit obligations, fair value of plan assets and the underfunded status for the Company’s Defined Benefit Pension, Post-Retirement Medical, and Supplemental Executive Retirement plans:



	Defined Benefit Pension Plan						Post-Retirement Medical Plan						Supplemental Executive Retirement Plan						Total
	Year Ended December 31,						Year Ended December 31,						Year Ended December 31,						Year Ended December 31,
	2017			2016			2017			2016			2017			2016			2017			2016
Change in projected benefit obligation:
Benefit obligation, January 1	$	592,290		$	560,817		$	19,031		$	16,637		$	44,501		$	43,858		$	655,822		$	621,312
Service cost	3,506			(1,403		)	1,457			1,246			(16		)	294			4,947			137
Interest cost	24,205			25,263			758			713			1,620			1,775			26,583			27,751
Actuarial (gain) loss	40,840			24,928			(1,216		)	1,408			(1,872		)	1,911			37,752			28,247
Regular benefits paid	(19,737		)	(17,315		)	(701		)	(973		)	(3,336		)	(3,337		)	(23,774		)	(21,625		)
Curtailments	(17,244		)	—			—			—			—			—			(17,244		)	—
Amendment	1,852			—			—			—			24			—			1,876			—
Benefit obligation, December 31	$	625,712		$	592,290		$	19,329		$	19,031		$	40,921		$	44,501		$	685,962		$	655,822
Accumulated benefit obligation	$	625,712		$	575,024		$	19,329		$	19,031		$	40,921		$	43,098		$	685,962		$	637,153

Schedule of fair value of plan assets



	Defined Benefit Pension Plan						Post-Retirement Medical Plan						Supplemental Executive Retirement Plan						Total
	Year Ended December 31,						Year Ended December 31,						Year Ended December 31,						Year Ended December 31,
	2017			2016			2017			2016			2017			2016			2017			2016
Change in plan assets:
Value of plan assets, January 1	$	453,087		$	427,131		$	—		$	—		$	—		$	—		$	453,087		$	427,131
Actual return on plan assets	50,292			43,271			—			—			—			—			50,292			43,271
Employer contributions	—			—			701			973			3,337			3,337			4,038			4,310
Benefits paid	(19,737		)	(17,315		)	(701		)	(973		)	(3,337		)	(3,337		)	(23,775		)	(21,625		)
Value of plan assets, December 31	$	483,642		$	453,087		$	—		$	—		$	—		$	—		$	483,642		$	453,087

Schedule of fair value of plan assets and the underfunded status



	Defined Benefit Pension Plan						Post-Retirement Medical Plan						Supplemental Executive Retirement Plan						Total
	December 31,						December 31,						December 31,						December 31,
	2017			2016			2017			2016			2017			2016			2017			2016
Under funded status at December 31	$	(142,070	)	$	(139,203	)	$	(19,329	)	$	(19,031	)	$	(40,921	)	$	(44,501	)	$	(202,320	)	$	(202,735	)

Schedule of amounts recognized in the consolidated balance sheets

The following table presents amounts recognized in the consolidated balance sheets for the Company’s Defined Benefit Pension, Post-Retirement Medical, and Supplemental Executive Retirement plans:



	Defined Benefit Pension Plan						Post-Retirement Medical Plan						Supplemental Executive Retirement Plan						Total
	December 31,						December 31,						December 31,						December 31,
	2017			2016			2017			2016			2017			2016			2017			2016
Amounts recognized in consolidated balance sheets:
Other liabilities	$	(142,070	)	$	(139,203	)	$	(19,329	)	$	(19,031	)	$	(40,921	)	$	(44,501	)	$	(202,320	)	$	(202,735	)
Accumulated other comprehensive income (loss)	(121,645		)	(133,055		)	6,276			5,715			(66		)	(2,360		)	(115,435		)	(129,700		)

Schedule of amounts recognized in AOCI that have not yet been recognized as components of net periodic benefit costs

The following table provides information regarding amounts in AOCI that have not yet been recognized as components of net periodic benefit cost at December 31, 2017:



	Defined Benefit Pension Plan						Post-Retirement Medical Plan				Supplemental Executive Retirement Plan						Total
	Gross			Net of tax			Gross		Net of tax		Gross			Net of tax			Gross			Net of tax
Net gain (loss)	$	(121,645	)	$	(96,098	)	$	6,105	$	4,823	$	1,157		$	914		$	(114,383	)	$	(90,361	)
Net prior service (cost) credit	—			—			171		135		(1,223		)	(966		)	(1,052		)	(831		)
	$	(121,645	)	$	(96,098	)	$	6,276	$	4,958	$	(66	)	$	(52	)	$	(115,435	)	$	(91,192	)

Schedule of information regarding amounts in AOCI that are expected to be recognized as components of net periodic benefit costs during the next fiscal year

The following table provides information regarding amounts in AOCI that are expected to be recognized as components of net periodic benefit costs during the year ended December 31, 2018:



	Defined Benefit Pension Plan						Post-Retirement Medical Plan				Supplemental Executive Retirement Plan						Total
	Gross			Net of tax			Gross		Net of tax		Gross			Net of tax			Gross			Net of tax
Net gain (loss)	$	(2,336	)	$	(1,845	)	$	276	$	218	$	45		$	36		$	(2,015	)	$	(1,591	)
Prior service (cost) credit	—			—			20		16		(324		)	(256		)	(304		)	(240		)
	$	(2,336	)	$	(1,845	)	$	296	$	234	$	(279	)	$	(220	)	$	(2,319	)	$	(1,831	)

Schedule of expected benefit payments

The expected benefit payments for the Company’s Defined Benefit Pension, Post-Retirement Medical, and Supplemental Executive Retirement plans for the years indicated are as follows:



	Defined Benefit Pension Plan		Post-Retirement Medical Plan		Supplemental Executive Retirement Plan
2018	$	20,286	$	795	$	2,515
2019	21,396		855		2,520
2020	22,737		873		2,480
2021	24,688		940		2,446
2022	26,676		1,003		10,180
2023 through 2027	158,881		6,579		13,065

Schedule of net periodic (benefit) cost

Net periodic (benefit) cost of the Defined Benefit Pension, Post-Retirement Medical, and Supplemental Executive Retirement plans included in general insurance expenses in the accompanying consolidated statements of income includes the following components:



	Defined Benefit Pension Plan
	Year Ended December 31,
	2017			2016			2015
Components of net periodic cost:
Service cost	$	3,506		$	(1,403	)	$	12,851
Interest cost	24,205			25,263			23,987
Expected return on plan assets	(20,626		)	(22,339		)	(28,345		)
Amortization of unrecognized prior service cost	—			—			13
Amortization of loss from earlier periods	7,190			10,260			12,398
Net periodic cost	$	14,275		$	11,781		$	20,904



	Post-Retirement Medical Plan
	Year Ended December 31,
	2017			2016			2015
Components of net periodic benefit:
Service cost	$	1,457		$	1,246		$	1,042
Interest cost	758			713			560
Amortization of unrecognized prior service benefit	(453		)	(1,102		)	(1,640		)
Amortization of gain from earlier periods	(202		)	(317		)	(511		)
Net periodic benefit	$	1,560		$	540		$	(549	)



	Supplemental Executive Retirement Plan
	Year Ended December 31,
	2017			2016			2015
Components of net periodic cost:
Service cost	$	(16	)	$	294		$	282
Interest cost	1,620			1,775			2,122
Amortization of unrecognized prior service cost	501			501			933
Amortization of loss from earlier periods	(54		)	(61		)	663
Net periodic cost	$	2,051		$	2,509		$	4,000

Schedule of weighted average interest rate assumptions used in determining benefit obligations

The following tables present the assumptions used in determining benefit obligations of the Defined Benefit Pension, Post-Retirement Medical, and the Supplemental Executive Retirement plans:



	Defined Benefit Pension Plan
	December 31,
	2017		2016
Discount rate	3.71	%	4.20	%
Rate of compensation increase	4.47	%	4.47	%



	Post-Retirement Medical Plan
	December 31,
	2017		2016
Discount rate	3.63	%	4.05	%
Initial health care cost trend	6.50	%	6.75	%
Ultimate health care cost trend	5.00	%	5.00	%
Year ultimate trend is reached	2024		2024



	Supplemental Executive Retirement Plan
	December 31,
	2017		2016
Discount rate	3.43	%	3.80	%
Rate of compensation increase	4.00	%	4.00	%

Schedule of weighted average interest rate assumptions used in determining the net periodic (benefit) cost

The following tables present the assumptions used in determining the net periodic (benefit) cost of the Defined Benefit Pension, Post-Retirement Medical, and the Supplemental Executive Retirement plans:



	Defined Benefit Pension Plan
	Year Ended December 31,
	2017		2016
Discount rate	4.20	%	4.55	%
Expected return on plan assets	5.25	%	6.00	%
Rate of compensation increase	4.47	%	4.47	%



	Post-Retirement Medical Plan
	Year Ended December 31,
	2017		2016
Discount rate	4.05	%	4.31	%
Initial health care cost trend	6.75	%	7.00	%
Ultimate health care cost trend	5.00	%	5.00	%
Year ultimate trend is reached	2024		2024



	Supplemental Executive Retirement Plan
	Year Ended December 31,
	2017		2016
Discount rate	3.80	%	4.22	%
Rate of compensation increase	4.00	%	4.00	%

Schedule of effect of one-percentage-point change in assumed healthcare cost trend rates

The following table presents the impact on the Post-Retirement Medical Plan that a one-percentage-point change in assumed health care cost trend rates would have on the following:



	One percentage point increase		One percentage point decrease
Increase (decrease) on total service and interest cost on components	$	371	$	(309	)
Increase (decrease) on post-retirement benefit obligation	2,524		(2,157		)

Schedule of investment of defined benefit pension plan assets

The following table presents how the Company’s Defined Benefit Pension Plan assets are invested:



	December 31,
	2017		2016
Equity securities	47	%	45	%
Debt securities	45	%	39	%
Other	8	%	16	%
Total	100	%	100	%

Schedule of defined benefit retirement plan assets measured at fair value on a recurring basis

The following tables present information about the Defined Benefit Retirement Plan’s assets measured at fair value on a recurring basis and indicates the fair value hierarchy of the valuation approach utilized to determine such fair value:



	Defined benefit plan assets measured at fair value on a recurring basis
	December 31, 2017
	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Common collective trust funds: ⁽¹⁾
Equity index funds	$	—	$	—	$	—	$	32,596
Midcap index funds	—		—		—		31,717
World equity index funds	—		—		—		60,216
U.S. equity market funds	—		—		—		46,400
International equity funds	—		—		—		15,382
Total common collective trust funds	—		—		—		186,311
Fixed maturity investments:
U.S. government direct obligations and agencies	—		4,608		—		4,608
Obligations of U.S. states and their municipalities	—		18,775		—		18,775
Corporate debt securities	—		183,462		1,108		184,570
Asset-backed securities	—		10,569		—		10,569
Commercial mortgage-backed securities	—		2,475		—		2,475
Total fixed maturity investments	—		219,889		1,108		220,997
Equity investments:
Fixed income mutual funds	27,516		—		—		27,516
Equity mutual funds	15,609		—		—		15,609
Preferred stock	704		—		—		704
Total equity investments	43,829		—		—		43,829
Limited partnership investments ⁽¹⁾	—		—		—		7,465
Money market funds	29,576		—		—		29,576
Total defined benefit plan assets	$	73,405	$	219,889	$	1,108	$	488,178

⁽¹⁾ Fair values of Common collective trust funds and Limited partnership investments are estimated using net asset value per unit as a practical expedient which are excluded from the disclosure requirement to classify amounts in the fair value hierarchy in connection with the adoption of ASU 2015-07.



	Defined benefit plan assets measured at fair value on a recurring basis
	December 31, 2016
	Quoted prices in active markets for identical assets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)		Total
Common collective trust funds: ⁽¹⁾
Equity index funds	$	—	$	—	$	—	$	34,578
Midcap index funds	—		—		—		35,330
World equity index funds	—		—		—		44,235
U.S. equity market funds	—		—		—		45,614
International equity funds	—		—		—		11,143
Total common collective trust funds	—		—		—		170,900
Fixed maturity investments:
U.S. government direct obligations and agencies	—		5,672		—		5,672
Obligations of U.S. states and their municipalities	—		18,670		—		18,670
Corporate debt securities	—		141,102		1,316		142,418
Asset-backed securities	—		7,828		—		7,828
Commercial mortgage-backed securities	—		2,884		—		2,884
Total fixed maturity investments	—		176,156		1,316		177,472
Equity investments:
Fixed income mutual funds	21,321		—		—		21,321
Equity mutual funds	11,106		—		—		11,106
Preferred stock	640		—		—		640
Total equity investments	33,067		—		—		33,067
Limited partnership investments ⁽¹⁾	—		—		—		7,022
Money market funds	62,883		—		—		62,883
Total defined benefit plan assets	$	95,950	$	176,156	$	1,316	$	451,344

Schedule of defined benefit retirement plan assets measured at fair value on a recurring basis for which Level 3 inputs are utilized

The following tables present additional information about assets of the Defined Benefit Retirement Plan measured at fair value on a recurring basis and for which the Company has utilized Level 3 inputs to determine fair value:



	Recurring Level 3 financial assets
	Corporate debt securities
	Year Ended December 31,
	2017			2016
Balance, January 1	$	1,316		$	—
Unrealized gains relating to instruments still held at reporting period	19			54
Settlements	(227		)	(213		)
Transfers into Level 3 ⁽¹⁾	—			1,475
Balance, December 31	$	1,108		$	1,316

⁽¹⁾ Transfers into Level 3 are due primarily to decreased observability of inputs in valuation methodologies.

Schedule of targets for the allocation of invested Defined Benefit Pension Plan assets

The following table presents the target allocation of invested Defined Benefit Pension Plan assets at December 31, 2018:



	December 31, 2018
Equity securities	30	%
Debt securities	52	%
Other	18	%
Total	100	%