COMMITMENTS AND CONTINGENT LIABILITIES - Schedule of Commitment Expiration (Details) $ in Thousands	Sep. 30, 2019 USD ($)
Guarantor Obligations [Line Items]
Total Amounts Committed	$ 754,661
Less Than 1 Year	602,269
1-3 Years	151,563
3-5 Years	398
Beyond 5 Years	431
Letters of Credit
Guarantor Obligations [Line Items]
Total Amounts Committed	113,634
Less Than 1 Year	79,592
1-3 Years	34,042
3-5 Years	0
Beyond 5 Years	0
Letters of Credit | Employee-Related
Guarantor Obligations [Line Items]
Total Amounts Committed	65,292
Less Than 1 Year	40,044
1-3 Years	25,248
3-5 Years	0
Beyond 5 Years	0
Letters of Credit | Environmental
Guarantor Obligations [Line Items]
Total Amounts Committed	398
Less Than 1 Year	398
1-3 Years	0
3-5 Years	0
Beyond 5 Years	0
Letters of Credit | Other
Guarantor Obligations [Line Items]
Total Amounts Committed	47,944
Less Than 1 Year	39,150
1-3 Years	8,794
3-5 Years	0
Beyond 5 Years	0
Surety Bonds
Guarantor Obligations [Line Items]
Total Amounts Committed	623,099
Less Than 1 Year	515,453
1-3 Years	107,646
3-5 Years	0
Beyond 5 Years	0
Surety Bonds | Employee-Related
Guarantor Obligations [Line Items]
Total Amounts Committed	87,174
Less Than 1 Year	74,424
1-3 Years	12,750
3-5 Years	0
Beyond 5 Years	0
Surety Bonds | Environmental
Guarantor Obligations [Line Items]
Total Amounts Committed	532,027
Less Than 1 Year	437,422
1-3 Years	94,605
3-5 Years	0
Beyond 5 Years	0
Surety Bonds | Other
Guarantor Obligations [Line Items]
Total Amounts Committed	3,898
Less Than 1 Year	3,607
1-3 Years	291
3-5 Years	0
Beyond 5 Years	0
Guarantees
Guarantor Obligations [Line Items]
Total Amounts Committed	17,928
Less Than 1 Year	7,224
1-3 Years	9,875
3-5 Years	398
Beyond 5 Years	431
Guarantees | Other
Guarantor Obligations [Line Items]
Total Amounts Committed	17,928
Less Than 1 Year	7,224
1-3 Years	9,875
3-5 Years	398
Beyond 5 Years	$ 431