Organization And Summary Of Significant Accounting Policies (Detail) (USD $)	12 Months Ended
	Apr. 30, 2012 Year	Apr. 30, 2011	Apr. 30, 2010
Organization and Accounting Policies Disclosure [Line Items]
Number of offices	76
Number of countries	35
Investments in affiliated companies maximum	50.00%
Dividends received from unconsolidated subsidiary	$ 1,669,000	$ 1,608,000	$ 958,000
Restricted cash	10,000,000	10,000,000
Realized loss of other-than-temporary impairment	0	0	0
Reduction in the estimated fair value of contingent consideration relating to prior acquisition	2,196,000	4,919,000
Impairment of goodwill	0	0
Intangible assets, estimated useful life, minimum (years)	3
Intangible assets, estimated useful life, maximum (years)	24
Trademark written-off		880,000
Performance related bonus expenses	116,800,000	128,300,000	76,900,000
Decrease in performance related bonus expenses	(1,200,000)	(2,000,000)	(3,600,000)
Performance related bonus after reduction in the previous year estimate	115,600,000	126,300,000	73,300,000
Deferred bonuses paid	5,400,000	10,200,000
Gross CSV	151,100,000	143,900,000
Outstanding policy loans	73,300,000	72,900,000
Receivable on insolvency of insurance companies	35,400,000	31,000,000
Foreign currency losses, after tax basis	1,600,000		2,000,000
Foreign currency gains, after tax basis		$ 100,000
Other Property And Equipment [Member]
Organization and Accounting Policies Disclosure [Line Items]
Property and equipment, estimated useful life, minimum (years)	3
Property and equipment, estimated useful life, maximum (years)	10
Software Development Costs [Member]
Organization and Accounting Policies Disclosure [Line Items]
Property and equipment, estimated useful life, minimum (years)	3
Property and equipment, estimated useful life, maximum (years)	7