RETIREMENT PLANS (Details) - USD ($)	1 Months Ended	3 Months Ended				9 Months Ended
	Oct. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Retirement Plans [Abstract]
Service period of participants not impacted by pension plan amendment						15 years
Age of plan participants not impacted by pension plan amendment						50 years
Service period of participants who are age fifty not impacted by pension plan amendment						10 years
Decrease in pension plan projected benefit obligation						$ (33,433,000)
Pension plan defined benefit plan cost increase limit percentage						4.00%
Higman [Member]
Retirement Plans [Abstract]
Decrease in pension plan projected benefit obligation						$ (3,081,000)
Pension contributions		$ 966,000	$ 966,000	$ 1,615,000
Subsequent Event [Member] | Higman [Member]
Retirement Plans [Abstract]
Pension contributions	$ 483,000
Pension Plan [Member]
Components of net periodic benefit cost [Abstract]
Service cost		1,841,000			$ 1,722,000	5,523,000	$ 5,816,000
Interest cost		4,123,000			3,939,000	12,370,000	11,544,000
Expected return on plan assets		(5,239,000)			(5,696,000)	(15,717,000)	(16,712,000)
Amortization of actuarial loss		359,000			723,000	1,078,000	2,168,000
Net periodic benefit cost		1,084,000			688,000	3,254,000	2,816,000
SERP [Member]
Components of net periodic benefit cost [Abstract]
Service cost		0			0	0	0
Interest cost		13,000			12,000	39,000	36,000
Expected return on plan assets		0			0	0	0
Amortization of actuarial loss		7,000			6,000	21,000	18,000
Net periodic benefit cost		20,000			18,000	60,000	54,000
Other Postretirement Benefits [Member]
Components of net periodic benefit cost [Abstract]
Service cost		0			0	0	0
Interest cost		7,000			6,000	23,000	18,000
Amortization of actuarial loss		(135,000)			(149,000)	(405,000)	(447,000)
Net periodic benefit cost		$ (128,000)			$ (143,000)	$ (382,000)	$ (429,000)