EMPLOYEE BENEFITS (Tables)

12 Months Ended

Dec. 31, 2018

Retirement Benefits [Abstract]

Summary of Actual and Target Asset Allocation of Plan Assets

The following is a summary of the pension plan's actual and target asset allocations at December 31, 2018 and 2017 by asset category:

									Target
Pension Plan Assets	2018		% of Total		2017		% of Total		Allocation
Fixed maturity securities - corporate bonds	$	10,051	6.1	%	$	11,003	7.0	%	0	%	-	15	%
Redeemable preferred stock	2,697		1.6		3,216		2.0		0	%	-	10	%
Equity securities	86,586		52.5		87,603		55.6		50	%	-	70	%
Pooled separate accounts
Core plus bond separate account fund	20,222		12.3		17,948		11.4		0	%	-	40	%
U.S. property separate account fund	20,841		12.6		15,502		9.8		0	%	-	25	%
Arbitrage fund	8,716		5.3		8,506		5.4		0	%	-	10	%
United Life annuity	10,339		6.3		9,846		6.2		5	%	-	10	%
Cash and cash equivalents	5,367		3.3		4,020		2.6		0	%	-	10	%
Total plan assets	$	164,819	100.0	%	$	157,644	100.0	%

Categories of Pension Plan Assets at Fair Value on Recurring Basis

The following tables present the categorization of the pension plan's assets measured at fair value on a recurring basis at December 31, 2018 and 2017:

			Fair Value Measurements
Description	December 31, 2018		Level 1		Level 2		Level 3
Fixed maturity securities - corporate bonds	$	10,051	$	—	$	10,051	$	—
Redeemable preferred stock	2,697		2,697		—		—
Equity securities	86,586		86,586		—		—
Pooled separate accounts
Core plus bond separate account fund	20,222		—		20,222		—
U.S. property separate account fund	20,841		—		—		20,841
Arbitrage fund	8,716		—		8,716		—
Money market funds	5,364		5,364		—		—
Total assets measured at fair value	$	154,477	$	94,647	$	38,989	$	20,841

			Fair Value Measurements
Description	December 31, 2017		Level 1		Level 2		Level 3
Fixed maturity securities - corporate bonds	$	11,003	$	—	$	11,003	$	—
Redeemable preferred stock	3,216		3,216		—		—
Equity securities	87,603		87,603		—		—
Pooled separate accounts
Core plus bond separate account fund	17,948		—		17,948		—
U.S. property separate account fund	15,502		—		—		15,502
Arbitrage fund	8,506		—		8,506		—
Money market funds	4,011		4,011		—		—
Total assets measured at fair value	$	147,789	$	94,830	$	37,457	$	15,502

Summary of Changes in Fair Value of Pension Plan Securities

The following tables provide a summary of the changes in fair value of the pension plan's Level 3 securities:

	U.S. property separate account fund
Balance at January 1, 2018	$	15,502
Unrealized gains	1,339
Company Contributions	4,000
Balance at December 31, 2018	$	20,841

	U.S. property separate account fund
Balance at January 1, 2017	$	14,330
Unrealized gains	1,172
Balance at December 31, 2017	$	15,502

Schedule of Actuarial Assumptions Used

The following actuarial assumptions were used to determine the reported plan benefit obligations at December 31:

Weighted-average assumptions as of	Pension Benefits				Post-retirement Benefits
December 31,	2018		2017		2018		2017
Discount rate	4.18	%	3.65	%	4.18	%	3.65	%
Rate of compensation increase	3.00		3.00		N/A		N/A

The following actuarial assumptions were used at January 1 to determine our reported net periodic benefit costs for the year ended December 31:

Weighted-average assumptions as of	Pension Benefits						Post-retirement Benefits
January 1,	2018		2017		2016		2018		2017		2016
Discount rate	3.65	%	4.17	%	4.21	%	3.65	%	4.17	%	4.21	%
Expected long-term rate of return on plan assets	6.70		7.50		7.50		N/A		N/A		N/A
Rate of compensation increase	3.00		3.00		3.00		N/A		N/A		N/A

Schedule of Health Care Cost Trend Rates

	Health Care Benefits				Dental Claims
Years Ended December 31,	2018		2017		2018		2017
Health care cost trend rates assumed for next year	6.75	%	7.00	%	4.00	%	4.00	%
Rate to which the health care trend rate is assumed to decline (ultimate trend rate)	4.50	%	4.50	%	N/A		N/A
Year that the rate reaches the ultimate trend rate	2029		2026		N/A		N/A

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

A 1.0 percent change in assumed health care cost trend rates would have the following effects:

	1% Increase		1% Decrease
Effect on the net periodic post-retirement health care benefit cost	$	677	$	(530	)
Effect on the accumulated post-retirement benefit obligation	5,066		(4,107		)

Reconciliation of Benefit Obligations, Plan Assets, and Funded Status

The following table provides a reconciliation of benefit obligations, plan assets and funded status of our plans:

	Pension Benefits						Post-retirement Benefits
Years Ended December 31,	2018			2017			2018			2017
Reconciliation of benefit obligation
Benefit obligation at beginning of year	$	208,349		$	171,876		$	55,728		$	46,785
Service cost	8,701			6,857			2,998			2,021
Interest cost	7,500			7,060			2,009			1,927
Actuarial loss	(17,535		)	26,963			(12,094		)	6,326
Adjustment for plan amendment	—			—			(16,159		)	—
Benefit payments	(4,859		)	(4,407		)	(1,509		)	(1,331		)
Benefit obligation at end of year (1)	$	202,156		$	208,349		$	30,973		$	55,728
Reconciliation of fair value of plan assets
Fair value of plan assets at beginning of year	$	157,644		$	128,430		$	—		$	—
Actual return on plan assets	(4,366		)	22,225			—			—
Employer contributions	16,400			11,396			1,509			1,331
Benefit payments	(4,859		)	(4,407		)	(1,509		)	(1,331		)
Fair value of plan assets at end of year	$	164,819		$	157,644		$	—		$	—
Funded status at end of year	$	(37,337	)	$	(50,705	)	$	(30,973	)	$	(55,728	)

(1)

For the pension plan, the benefit obligation is the projected benefit obligation. For the post-retirement benefit plan, the benefit obligation is the accumulated post-retirement benefit obligation.

Schedule of Amounts Recognized in AOCI

The following table displays the effect that the unrecognized prior service cost and unrecognized actuarial loss of our plans had on accumulated other comprehensive income ("AOCI"), as reported in the accompanying Consolidated Balance Sheets:

	Pension Benefits				Post-retirement Benefits
Years Ended December 31	2018		2017		2018			2017
Amounts recognized in AOCI
Unrecognized prior service cost	$	—	$	—	$	(37,631	)	$	(26,880	)
Unrecognized actuarial (gain) loss	53,616		60,571		10,786			25,235
Total amounts recognized in AOCI	$	53,616	$	60,571	$	(26,845	)	$	(1,645	)

Components of Net Periodic Benefit Cost

The components of the net periodic benefit cost for our pension and post-retirement benefit plans are as follows:

	Pension Plan									Post-retirement Benefit Plan
Years Ended December 31,	2018			2017			2016			2018			2017			2016
Net periodic benefit cost
Service cost	$	8,701		$	6,857		$	6,490		$	2,998		$	2,021		$	3,728
Interest cost	7,500			7,060			6,654			2,009			1,927			3,015
Expected return on plan assets	(10,502		)	(9,650		)	(7,952		)	—			—			—
Amortization of prior service cost	—			—			—			(5,409		)	(5,409		)	—
Amortization of net loss	4,287			3,562			3,968			2,355			1,846			1,518
Net periodic benefit cost	$	9,986		$	7,829		$	9,160		$	1,953		$	385		$	8,261

A portion of the service cost component of net periodic pension and postretirement benefit costs are capitalized and amortized as part of deferred acquisition costs and is included in the income statement line titled "amortization of deferred policy acquisition costs." The portion not related to the compensation and the other components of net periodic pension and postretirement benefit costs are included in the income statement line titled "other underwriting expenses."

Summary of Expected Benefit Payments

The following table summarizes the expected benefits to be paid from our plans over the next 10 years:

	2019		2020		2021		2022		2023		2024 - 2028
Pension benefits	$	6,280	$	6,870	$	7,570	$	8,230	$	8,940	$	55,930
Post-retirement benefits	$	960	$	1,030	$	1,120	$	1,210	$	1,300	$	8,480