Non-operating income (expense) (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Apr. 30, 2013
Apr. 30, 2012
Apr. 30, 2013
Apr. 30, 2012
Non-operating income (expense)        
Interest and other income $ 3,423 $ 1,956 $ 4,027 $ 3,693
Net gains on investments and derivatives 1,475 1,250 6,226 7,680
Net foreign currency gains (losses) gains 145 (410) (3) (400)
Gains and other investment income, net 5,043 2,796 10,250 10,973
Interest expense (8,572) (8,412) (17,142) (16,825)
Other income (expense) of consolidated CLO entity:        
Interest income 4,071 5,668 8,916 11,212
Net gains (losses) on bank loans, other investments and note obligations 313 3,227 (2,739) 7,963
Gains and other investment income, net 4,384 8,895 6,177 19,175
Interest expense (3,051) (4,134) (7,272) (8,445)
Total non-operating (expense) income $ (2,196) $ (855) $ (7,987) $ 4,878