Fair Value Measurements - Level 3 Liabilities (Details) - USD ($)
3 Months Ended
Jan. 31, 2016
Oct. 31, 2015
Jul. 31, 2015
Apr. 30, 2015
Jan. 31, 2015
Oct. 31, 2014
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3            
Beginning balance $ 2,050,000 $ 2,777,000 $ 2,774,000 $ 5,701,000 $ 5,807,000 $ 5,869,000
Total net unrealized (gains) losses included in general and administrative expense in earnings 21,000 (592,000) 52,000 (2,790,000) 127,000 147,000
Settlements (100,000) (120,000) (109,000) (161,000) (164,000) (132,000)
Foreign currency translation (53,000) (15,000) 60,000 24,000 (69,000) (77,000)
Ending balance 1,918,000 2,050,000 2,777,000 2,774,000 5,701,000 5,807,000
Contingent Consideration | Jet Prep Ltd.            
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3            
Beginning balance 139,000 751,000 729,000 2,888,000 2,804,000 2,722,000
Total net unrealized (gains) losses included in general and administrative expense in earnings 4,000 (612,000) 22,000 (2,159,000) 84,000 82,000
Ending balance 143,000 139,000 751,000 729,000 2,888,000 2,804,000
Assumed contingent liability | Jet Prep Ltd.            
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3            
Beginning balance 1,138,000 1,138,000 1,131,000 1,773,000 1,763,000 1,752,000
Total net unrealized (gains) losses included in general and administrative expense in earnings     7,000 (642,000) 10,000 11,000
Ending balance 1,138,000 1,138,000 1,138,000 1,131,000 1,773,000 1,763,000
Contingent guaranteed obligation | Cantel Medical UK            
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3            
Beginning balance 773,000 888,000 914,000 1,040,000 1,240,000 1,395,000
Total net unrealized (gains) losses included in general and administrative expense in earnings 17,000 20,000 23,000 11,000 33,000 54,000
Settlements (100,000) (120,000) (109,000) (161,000) (164,000) (132,000)
Foreign currency translation (53,000) (15,000) 60,000 24,000 (69,000) (77,000)
Ending balance $ 637,000 $ 773,000 $ 888,000 $ 914,000 $ 1,040,000 $ 1,240,000