Estimated Fair Values of Aggregate Assets and Liabilities Acquired (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash	$ 40,360	$ 61,786
Other current assets	53,276	71,637
Fixed assets	1,825	4,766
Goodwill	278,553	361,118
Purchased customer accounts	106,389	120,603
Non-compete agreements	2,831	233
Other assets	1	1
Total assets acquired	483,235	620,144
Other current liabilities	(80,796)	(109,356)
Deferred income taxes, net	(18,867)	(26,423)
Other liabilities	(2,165)
Total liabilities assumed	(101,828)	(135,779)
Net assets acquired	381,407	484,365
Arrowhead General Insurance Agency Superholding Corporation [Member]
Cash		61,786
Other current assets		69,051
Fixed assets		4,629
Goodwill	(454)	322,779
Purchased customer accounts		99,515
Non-compete agreements		100
Other assets		1
Total assets acquired	(454)	557,861
Other current liabilities		(107,579)
Deferred income taxes, net		(26,423)
Total liabilities assumed		(134,002)
Net assets acquired	(454)	423,859
Insurcorp & GGM Investments LLC [Member]
Other current assets		180
Fixed assets		25
Goodwill	(566)	14,745
Purchased customer accounts	(268)	6,490
Non-compete agreements		22
Total assets acquired	(834)	21,462
Other current liabilities		(118)
Total liabilities assumed		(118)
Net assets acquired	(834)	21,344
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	1,882
Fixed assets		45
Goodwill	(843)	10,776
Purchased customer accounts	708	6,227
Non-compete agreements		14
Total assets acquired	(110)	18,944
Other current liabilities	3	(132)
Total liabilities assumed	3	(132)
Net assets acquired	(107)	18,812
The Rollins Agency, Inc. [Member]
Other current assets	393
Fixed assets	30
Goodwill	12,697
Purchased customer accounts	3,878
Non-compete agreements	31
Total assets acquired	17,029
Other current liabilities	(866)
Total liabilities assumed	(866)
Net assets acquired	16,163
Beecher Carlson Holdings, Inc. [Member]
Cash	40,360
Other current assets	51,330
Fixed assets	1,786
Goodwill	267,731
Purchased customer accounts	101,565
Non-compete agreements	2,758
Total assets acquired	465,530
Other current liabilities	(79,855)
Deferred income taxes, net	(18,867)
Other liabilities	(2,165)
Total liabilities assumed	(100,887)
Net assets acquired	364,643
Other Acquisitions [Member]
Other current assets	1,528	524
Fixed assets	9	67
Goodwill	(228)	12,818
Purchased customer accounts	502	8,371
Non-compete agreements	42	97
Other assets	1
Total assets acquired	1,854	21,877
Other current liabilities	(78)	(1,527)
Total liabilities assumed	(78)	(1,527)
Net assets acquired	$ 1,776	$ 20,350