ACCRUED EXPENSES AND OTHER LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Accrued Expenses
Salaries and wages	$ 167,568	$ 158,122
Deferred compensation	5,613	5,117
Pension benefits	3,787	3,776
Other postretirement benefits	1,386	1,381
Other employee benefits	13,755	20,599
Insurance obligations	174,582	169,936
Operating taxes	174,058	164,293
Income taxes	3,133	4,588
Interest	38,129	38,887
Deposits, mainly from customers	90,349	79,840
Operating lease liabilities	80,657	78,785
Deferred revenue	187,467	183,474
Restructuring liabilities	3,293	7,683
Other	77,055	72,697
Total	1,020,832	989,178
Non-Current Liabilities
Salaries and wages	0	0
Deferred compensation	84,975	77,823
Pension benefits	258,341	265,178
Other postretirement benefits	17,490	20,245
Other employee benefits	0	0
Insurance obligations	300,086	292,298
Operating taxes	41,683	41,687
Income taxes	16,326	15,598
Interest	0	0
Deposits, mainly from customers	3,014	3,014
Operating lease liabilities	172,377	186,429
Deferred revenue	425,669	446,265
Restructuring liabilities	0	0
Other	51,092	55,324
Total	1,371,053	1,403,861
Total
Salaries and wages	167,568	158,122
Deferred compensation	90,588	82,940
Pension benefits	262,128	268,954
Other postretirement benefits	18,876	21,626
Other employee benefits	13,755	20,599
Insurance obligations	474,668	462,234
Operating taxes	215,741	205,980
Income taxes	19,459	20,186
Interest	38,129	38,887
Deposits, mainly from customers	93,363	82,854
Operating lease liabilities	253,034	265,214
Deferred revenue	613,136	629,739	$ 613,972	$ 603,687
Restructuring liabilities	3,293	7,683
Other	128,147	128,021
Total	$ 2,391,885	$ 2,393,039