Goodwill (Key Ratios Used to Measure Goodwill of Property and Casualty Insurance Reporting Unit for Impairment) (Detail) (Property And Casualty Insurance Reporting Unit [Member], USD $) In Thousands, unless otherwise specified	May 31, 2013 Ratios	May 31, 2012
Goodwill [Line Items]
Goodwill	$ 17,177	$ 17,177
Number of key ratios used	2
Fair value of the property and casualty insurance reporting unit exceeding carrying value	21.70%	7.30%
Annual [Member]
Goodwill [Line Items]
Average price to book	1.15	1.17
Median price to earnings	18.1	12.1