Equity and Comprehensive Income (Loss) - Summary of Changes in Equity (Detail) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 1,047.5	$ 957.9
Net income	$ 51.9	$ 39.9	112.0	47.9
Other comprehensive income (loss):
Foreign currency translation	(26.3)	10.4	12.1	1.2
Derivative financial instruments	1.4	0.2	5.3	4.8
Minimum pension liabilities	2.7	1.3	1.8	29.4
Comprehensive income	29.7	51.8	131.2	83.3
Current period mark to redemption value of redeemable noncontrolling interest			(1.8)
Net income allocated to redeemable noncontrolling interests			(1.9)	(2.2)
Other				(2.6)
Dividends paid to Greif, Inc. shareholders	(24.8)	(24.7)	(49.3)	(49.2)
Dividends paid to noncontrolling interests			(2.7)	(3.1)
Restricted stock directors			1.0
Long-term incentive shares issued			5.3	2.7
Ending balance	1,129.3	986.8	1,129.3	986.8
Other comprehensive income (loss), derivatives qualifying as hedges, tax		2.9	1.8
Other comprehensive (income) loss, pension and other postretirement benefit plans, tax			0.0	17.5
Greif, Inc. Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			1,010.9	947.4
Net income			101.6	41.4
Other comprehensive income (loss):
Foreign currency translation			11.7	3.5
Derivative financial instruments			5.3	4.8
Minimum pension liabilities			1.8	29.4
Comprehensive income			120.4	79.1
Current period mark to redemption value of redeemable noncontrolling interest			(1.8)
Dividends paid to Greif, Inc. shareholders			(49.3)	(49.2)
Restricted stock directors			1.0
Long-term incentive shares issued			5.3	2.7
Ending balance	1,086.5	980.0	$ 1,086.5	$ 980.0
Capital Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (shares)			47,843	47,792
Beginning balance			$ 144.2	$ 141.4
Other comprehensive income (loss):
Restricted stock directors (shares)			21
Restricted stock directors			$ 1.0
Long-term incentive shares issued (shares)			85	49
Long-term incentive shares issued			$ 5.1	$ 2.6
Ending balance	$ 150.3	$ 144.0	$ 150.3	$ 144.0
Ending balance (shares)	47,949	47,841	47,949	47,841
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (shares)			28,999	29,050
Beginning balance			$ (135.6)	$ (135.6)
Other comprehensive income (loss):
Restricted stock directors (shares)			21
Restricted stock directors			$ 0.0
Long-term incentive shares issued (shares)			85	49
Long-term incentive shares issued			$ 0.2	$ 0.1
Ending balance	$ (135.4)	$ (135.5)	$ (135.4)	$ (135.5)
Ending balance (shares)	28,893	29,001	28,893	29,001
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 1,360.5	$ 1,340.0
Net income			101.6	41.4
Other comprehensive income (loss):
Derivative financial instruments			(0.6)
Current period mark to redemption value of redeemable noncontrolling interest			(1.8)
Dividends paid to Greif, Inc. shareholders			(49.3)	(49.2)
Ending balance	$ 1,410.4	$ 1,332.2	1,410.4	1,332.2
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			(358.2)	(398.4)
Other comprehensive income (loss):
Foreign currency translation			11.7	3.5
Derivative financial instruments			5.9	4.8
Minimum pension liabilities			1.8	29.4
Ending balance	(338.8)	(360.7)	(338.8)	(360.7)
Non controlling interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			36.6	10.5
Net income			10.4	6.5
Other comprehensive income (loss):
Foreign currency translation			0.4	(2.3)
Net income allocated to redeemable noncontrolling interests			(1.9)	(2.2)
Other				(2.6)
Dividends paid to noncontrolling interests			(2.7)	(3.1)
Ending balance	$ 42.8	$ 6.8	$ 42.8	$ 6.8