PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Fair Value Assumptions of Plan Assets) (Details) - USD ($) $ in Thousands	Apr. 01, 2018	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	$ 113,825	$ 112,570
Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	6,128
Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	113,825	106,442
Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	6,128
Cash and cash equivalents | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	6,128
Cash and cash equivalents | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Large U.S. equity funds | Pooled separate accounts
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	2,942	3,483
Large U.S. equity funds | Pooled separate accounts | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Large U.S. equity funds | Pooled separate accounts | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	2,942	3,483
Large U.S. equity funds | Pooled separate accounts | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Large U.S. equity funds | Common collective trusts funds
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	18,684	22,695
Large U.S. equity funds | Common collective trusts funds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Large U.S. equity funds | Common collective trusts funds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	18,684	22,695
Large U.S. equity funds | Common collective trusts funds | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Small/Mid U.S. equity funds | Pooled separate accounts
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	367	420
Small/Mid U.S. equity funds | Pooled separate accounts | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Small/Mid U.S. equity funds | Pooled separate accounts | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	367	420
Small/Mid U.S. equity funds | Pooled separate accounts | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Small/Mid U.S. equity funds | Common collective trusts funds
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	8,365	20,592
Small/Mid U.S. equity funds | Common collective trusts funds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Small/Mid U.S. equity funds | Common collective trusts funds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	8,365	20,592
Small/Mid U.S. equity funds | Common collective trusts funds | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
International equity funds | Pooled separate accounts
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	1,793	1,665
International equity funds | Pooled separate accounts | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
International equity funds | Pooled separate accounts | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	1,793	1,665
International equity funds | Pooled separate accounts | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
International equity funds | Common collective trusts funds
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	25,403	19,923
International equity funds | Common collective trusts funds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
International equity funds | Common collective trusts funds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	25,403	19,923
International equity funds | Common collective trusts funds | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Fixed income funds | Pooled separate accounts
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	5,133	4,799
Fixed income funds | Pooled separate accounts | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Fixed income funds | Pooled separate accounts | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	5,133	4,799
Fixed income funds | Pooled separate accounts | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Fixed income funds | Common collective trusts funds
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	46,046	32,865
Fixed income funds | Common collective trusts funds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Fixed income funds | Common collective trusts funds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	46,046	32,865
Fixed income funds | Common collective trusts funds | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Real estate | Common collective trusts funds
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	5,092	0
Real estate | Common collective trusts funds | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	0	0
Real estate | Common collective trusts funds | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	5,092	0
Real estate | Common collective trusts funds | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Fair value of plan assets	$ 0	$ 0