Earnings Per Share - Computation of Earnings Per Share Basic and Diluted (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Numerator for basic and diluted EPS
Net income attributable to Greif	$ 8.5	$ 46.1	$ 31.4	$ (11.1)	$ 12.4	$ 8.6	$ 20.8	$ 30.1	$ 74.9	$ 71.9	$ 91.5
Cash dividends									98.7	98.7	98.6
Undistributed net loss attributable to Greif, Inc.									$ (23.8)	$ (26.8)	$ (7.1)
Class A Common Stock
Denominator for basic EPS
Denominator for basic EPS (shares)	25,781,791	25,781,146	25,761,733	25,697,512	25,693,564	25,692,973	25,678,393	25,607,886	25,755,545	25,668,204	25,547,650
Denominator for diluted EPS
Denominator for diluted EPS (shares)	25,785,266	25,783,184	25,766,609	25,704,023	25,701,264	25,698,547	25,688,653	25,617,814	25,756,893	25,674,105	25,552,986
EPS Basic
EPS Basic (usd per share)	$ 0.14	$ 0.78	$ 0.53	$ (0.19)	$ 0.21	$ 0.15	$ 0.35	$ 0.52	$ 1.28	$ 1.23	$ 1.56
EPS Diluted
EPS Diluted (usd per share)	$ 0.14	$ 0.78	$ 0.53	$ (0.19)	$ 0.21	$ 0.15	$ 0.35	$ 0.52	$ 1.28	$ 1.23	$ 1.56
Class B Common Stock
Denominator for basic EPS
Denominator for basic EPS (shares)	22,009,725	22,009,725	22,108,942	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,100,000	22,100,000	22,100,000
Denominator for diluted EPS
Denominator for diluted EPS (shares)	22,009,725	22,009,725	22,108,942	22,119,966	22,119,966	22,119,966	22,119,966	22,119,966	22,100,000	22,100,000	22,100,000
EPS Basic
EPS Basic (usd per share)	$ 0.22	$ 1.18	$ 0.80	$ (0.29)	$ 0.32	$ 0.22	$ 0.53	$ 0.76	$ 1.90	$ 1.83	$ 2.33
EPS Diluted
EPS Diluted (usd per share)	$ 0.22	$ 1.18	$ 0.80	$ (0.29)	$ 0.32	$ 0.22	$ 0.53	$ 0.76	$ 1.90	$ 1.83	$ 2.33