Summarized Financial Information Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total revenues	$ 335,012	$ 302,486
Investment income	186	135
Amortization	16,161	15,613
Depreciation	4,167	3,641
Interest expense	3,984	4,087
Income before income taxes	99,491	82,790
Total assets	3,230,360	3,017,447	3,128,058
Capital expenditures	2,947	5,905
Retail [Member]
Segment Reporting Information [Line Items]
Total revenues	174,568	167,204
Investment income	23	25
Amortization	8,811	8,527
Depreciation	1,371	1,258
Interest expense	6,200	6,934
Income before income taxes	46,211	42,200
Total assets	2,483,391	2,188,467
Capital expenditures	1,335	1,061
National Programs [Member]
Segment Reporting Information [Line Items]
Total revenues	68,940	64,607
Investment income	5
Amortization	3,519	3,176
Depreciation	1,248	1,142
Interest expense	5,694	6,652
Income before income taxes	14,012	15,957
Total assets	1,194,383	1,154,666
Capital expenditures	892	2,416
Wholesale Brokerage [Member]
Segment Reporting Information [Line Items]
Total revenues	48,697	43,304
Investment income	5	6
Amortization	2,897	2,787
Depreciation	707	656
Interest expense	755	1,226
Income before income taxes	10,362	8,877
Total assets	882,273	768,444
Capital expenditures	536	1,174
Services [Member]
Segment Reporting Information [Line Items]
Total revenues	42,647	25,830
Investment income	1
Amortization	924	1,113
Depreciation	397	225
Interest expense	1,921	1,520
Income before income taxes	13,953	2,987
Total assets	248,882	269,623
Capital expenditures	119	361
Other [Member]
Segment Reporting Information [Line Items]
Total revenues	160	1,541
Investment income	152	104
Amortization	10	10
Depreciation	444	360
Interest expense	(10,586)	(12,245)
Income before income taxes	14,953	12,769
Total assets	(1,578,569)	(1,363,753)
Capital expenditures	$ 65	$ 893