EQUITY AND COMPREHENSIVE INCOME (LOSS) - Summary of Changes in Equity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Jan. 31, 2020	Jan. 31, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,191.1	$ 1,154.2
Net income	36.1	35.8
Other comprehensive income (loss):
Foreign currency translation	(3.1)	5.2
Derivative financial instruments, net of income tax benefit of $1.9 million		(5.7)
Derivative financial instruments, net of immaterial income tax expense	0.2	(5.7)
Minimum pension liabilities	21.7	(0.8)
Comprehensive income	54.9	34.5
Current period mark to redemption value of redeemable noncontrolling interest	3.3	0.2
Net income allocated to redeemable noncontrolling interests	(0.1)	(0.8)
Dividends paid to Greif, Inc. shareholders	(25.9)	(25.7)
Dividends paid to noncontrolling interests and other	(0.8)	(0.4)
Restricted stock, executive	0.2
Cumulative Effect of New Accounting Principle in Period of Adoption		(2.1)
Long-term incentive shares issued		11.6
Ending balance	$ 1,222.7	1,171.5
Other comprehensive income (loss), derivatives qualifying as hedges, tax		$ 1.9
Capital Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (shares)	48,266	47,949
Beginning balance	$ 162.6	$ 150.5
Other comprehensive income (loss):
Restricted stock, executive (shares)	3
Restricted stock, executive	$ 0.1
Long-term incentive shares issued (shares)		292
Long-term incentive shares issued		$ 11.0
Ending balance	$ 162.7	$ 161.5
Ending balance (shares)	48,269	48,241
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (shares)	28,576	28,893
Beginning balance	$ (134.8)	$ (135.4)
Other comprehensive income (loss):
Restricted stock, executive (shares)	(3)
Restricted stock, executive	$ 0.1
Long-term incentive shares issued (shares)		(292)
Long-term incentive shares issued		$ 0.6
Ending balance	$ (134.7)	$ (134.8)
Ending balance (shares)	28,573	28,601
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,539.0	$ 1,469.8
Net income	32.3	29.7
Other comprehensive income (loss):
Current period mark to redemption value of redeemable noncontrolling interest	3.3	0.2
Dividends paid to Greif, Inc. shareholders	(25.9)	(25.7)
Cumulative Effect of New Accounting Principle in Period of Adoption		(2.1)
Ending balance	1,548.7	1,471.9
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(433.7)	(377.1)
Other comprehensive income (loss):
Foreign currency translation	(1.1)	4.2
Derivative financial instruments, net of income tax benefit of $1.9 million		(5.7)
Derivative financial instruments, net of immaterial income tax expense	0.2
Minimum pension liabilities	21.7	(0.8)
Ending balance	(412.9)	(379.4)
Income tax expense	7.5
Greif, Inc. Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,133.1	1,107.8
Net income	32.3	29.7
Other comprehensive income (loss):
Foreign currency translation	(1.1)	4.2
Derivative financial instruments, net of income tax benefit of $1.9 million		(5.7)
Derivative financial instruments, net of immaterial income tax expense	0.2
Minimum pension liabilities	21.7	(0.8)
Comprehensive income	53.1	27.4
Current period mark to redemption value of redeemable noncontrolling interest	3.3	0.2
Dividends paid to Greif, Inc. shareholders	(25.9)	(25.7)
Restricted stock, executive	0.2
Cumulative Effect of New Accounting Principle in Period of Adoption		(2.1)
Long-term incentive shares issued		11.6
Ending balance	1,163.8	1,119.2
Non controlling interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	58.0	46.4
Net income	3.8	6.1
Other comprehensive income (loss):
Foreign currency translation	(2.0)	1.0
Net income allocated to redeemable noncontrolling interests	(0.1)	(0.8)
Dividends paid to noncontrolling interests and other	(0.8)	(0.4)
Ending balance	$ 58.9	$ 52.3
Class A Common Stock
Other comprehensive income (loss):
Dividends (in usd per share)	$ 0.44	$ 0.44
Class B Common Stock
Other comprehensive income (loss):
Dividends (in usd per share)	$ 0.65	$ 0.65