Estimated Fair Values of Aggregate Assets and Liabilities Acquired (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Cash		$ 62,396
Other current assets	1,444	66,938
Fixed assets		4,768
Goodwill	(2,861)	323,044
Purchased customer accounts	346	101,900
Non-compete agreements		154
Other assets		41
Total assets acquired	(1,071)	559,241
Other current liabilities	(43)	(105,238)
Deferred income taxes, net		(26,651)
Total liabilities assumed	(43)	(131,889)
Net Assets Acquired	(1,114)	427,352
Arrowhead General Insurance Agency Superholding Corporation [Member]
Cash		62,396
Other current assets		66,828
Fixed assets		4,743
Goodwill	(454)	320,145
Purchased customer accounts		100,072
Non-compete agreements		100
Other assets		41
Total assets acquired	(454)	554,325
Other current liabilities		(105,118)
Deferred income taxes, net		(26,651)
Total liabilities assumed		(131,769)
Net Assets Acquired	(454)	422,556
Insurcorp & GGM Investments LLC [Member]
Goodwill	(566)
Purchased customer accounts	(268)
Total assets acquired	(834)
Net Assets Acquired	(834)
Richard W. Endlar Insurance Agency, Inc. [Member]
Goodwill	216
Purchased customer accounts	4
Total assets acquired	220
Net Assets Acquired	220
Texas Security General Insurance Agency Inc. [Member]
Other current assets	25
Goodwill	(843)
Purchased customer accounts	708
Total assets acquired	(110)
Other current liabilities	3
Net Assets Acquired	(107)
Other Acquisitions [Member]
Other current assets	1,419	110
Fixed assets		25
Goodwill	(1,214)	2,899
Purchased customer accounts	(98)	1,828
Non-compete agreements		54
Total assets acquired	107	4,916
Other current liabilities	(46)	(120)
Total liabilities assumed		(120)
Net Assets Acquired	$ 61	$ 4,796