Business Combinations (Estimated Fair Values Of The Aggregate Assets And Liabilities Acquired) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Business Acquisition [Line Items]
Cash	$ 62,396
Other current assets	66,938	267
Fixed assets	4,768	172
Goodwill	323,044	34,324
Purchased customer accounts	101,900	19,149
Non-compete agreements	154	212
Other assets	41	4
Total assets acquired	559,241	54,128
Other current liabilities	(105,238)	(782)
Deferred income taxes, net	(26,651)
Total liabilities assumed	(131,889)	(782)
Net assets acquired	427,352	53,346
Arrowhead General Insurance Agency Superholding Corporation [Member]
Business Acquisition [Line Items]
Cash	62,396
Other current assets	66,828
Fixed assets	4,743
Goodwill	320,145
Purchased customer accounts	100,072
Non-compete agreements	100
Other assets	41
Total assets acquired	554,325
Other current liabilities	(105,118)
Deferred income taxes, net	(26,651)
Total liabilities assumed	(131,769)
Net assets acquired	422,556
Balcos Insurance, Inc., Et Al [Member]
Business Acquisition [Line Items]
Cash
Fixed assets		20
Goodwill		6,651
Purchased customer accounts		3,530
Non-compete agreements		42
Total assets acquired		10,243
Other current liabilities		(37)
Total liabilities assumed		(37)
Net assets acquired		10,206
Associated Insurance Service, Inc., Et Al [Member]
Business Acquisition [Line Items]
Cash
Fixed assets		100
Goodwill		9,297
Purchased customer accounts		4,086
Non-compete agreements		92
Total assets acquired		13,575
Net assets acquired		13,575
United Benefit Services Insurance Agency, Et Al [Member]
Business Acquisition [Line Items]
Cash
Fixed assets		20
Goodwill		10,661
Purchased customer accounts		6,787
Non-compete agreements		45
Other assets		4
Total assets acquired		17,517
Other current liabilities		(35)
Total liabilities assumed		(35)
Net assets acquired		17,482
Other [Member]
Business Acquisition [Line Items]
Cash
Other current assets	110	267
Fixed assets	25	32
Goodwill	2,899	7,715
Purchased customer accounts	1,828	4,746
Non-compete agreements	54	33
Total assets acquired	4,916	12,793
Other current liabilities	(120)	(710)
Total liabilities assumed	(120)	(710)
Net assets acquired	$ 4,796	$ 12,083