Non-operating income (expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2010
Non-operating income (expense)
Interest and other income	$ 7,922	$ 7,508	$ 5,471
Net gains on investments and derivatives	10,957	11,926	7,394
Net foreign currency gains (losses)	(462)	(26)	181
Gains and other investment income, net	18,417	19,408	13,046
Interest expense	(33,930)	(33,652)	(33,666)
Other income (expense) of consolidated CLO entity:
Interest income	22,058	21,116	0
Net gains (losses) on bank loans, other investments and note obligations	22,648	(38,153)	0
Gains (losses) and other investment income, net	44,706	(17,037)	0
Interest expense	(18,447)	(13,575)	0
Total non-operating income (expense)	$ 10,746	$ (44,856)	$ (20,620)