Summarized Quarterly Information - Restated (Unaudited) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended			3 Months Ended											12 Months Ended		3 Months Ended											12 Months Ended		3 Months Ended											12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2012 Scenario, Previously Reported [Member]	Jun. 30, 2012 Scenario, Previously Reported [Member]	Mar. 31, 2012 Scenario, Previously Reported [Member]	Dec. 31, 2011 Scenario, Previously Reported [Member]	Sep. 30, 2011 Scenario, Previously Reported [Member]	Jun. 30, 2011 Scenario, Previously Reported [Member]	Mar. 31, 2011 Scenario, Previously Reported [Member]	Dec. 31, 2010 Scenario, Previously Reported [Member]	Sep. 30, 2010 Scenario, Previously Reported [Member]	Jun. 30, 2010 Scenario, Previously Reported [Member]	Mar. 31, 2010 Scenario, Previously Reported [Member]	Dec. 31, 2011 Scenario, Previously Reported [Member]	Dec. 31, 2010 Scenario, Previously Reported [Member]	Sep. 30, 2012 Restatement Adjustment [Member]	Jun. 30, 2012 Restatement Adjustment [Member]	Mar. 31, 2012 Restatement Adjustment [Member]	Dec. 31, 2011 Restatement Adjustment [Member]	Sep. 30, 2011 Restatement Adjustment [Member]	Jun. 30, 2011 Restatement Adjustment [Member]	Mar. 31, 2011 Restatement Adjustment [Member]	Dec. 31, 2010 Restatement Adjustment [Member]	Sep. 30, 2010 Restatement Adjustment [Member]	Jun. 30, 2010 Restatement Adjustment [Member]	Mar. 31, 2010 Restatement Adjustment [Member]	Dec. 31, 2011 Restatement Adjustment [Member]	Dec. 31, 2010 Restatement Adjustment [Member]	Sep. 30, 2012 Scenario, Actual [Member]	Jun. 30, 2012 Scenario, Actual [Member]	Mar. 31, 2012 Scenario, Actual [Member]	Dec. 31, 2011 Scenario, Actual [Member]	Sep. 30, 2011 Scenario, Actual [Member]	Jun. 30, 2011 Scenario, Actual [Member]	Mar. 31, 2011 Scenario, Actual [Member]	Dec. 31, 2010 Scenario, Actual [Member]	Sep. 30, 2010 Scenario, Actual [Member]	Jun. 30, 2010 Scenario, Actual [Member]	Mar. 31, 2010 Scenario, Actual [Member]	Dec. 31, 2011 Scenario, Actual [Member]	Dec. 31, 2010 Scenario, Actual [Member]
Service and administrative fees									$ 90,550		$ 56,254		$ 9,394	$ 9,340	$ 10,159	$ 10,125	$ 8,800	$ 9,116	$ 8,098	$ 9,229	$ 8,843	$ 7,975	$ 38,200	$ 34,145		$ 12,392	$ 13,171	$ 15,036	$ 16,831	$ 12,321	$ 12,076	$ 10,289	$ 8,738	$ 3,082	$ 0	$ 56,264	$ 22,109	$ 22,898	$ 21,786	$ 22,511	$ 25,195	$ 26,956	$ 21,121	$ 21,192	$ 18,387	$ 17,967	$ 11,925	$ 7,975	$ 94,464	$ 56,254
Revenues	71,605	77,104	71,058	71,879	75,363	73,282	66,172	66,772	291,646	281,589	226,399	64,262	58,666	58,708	60,327	56,451	53,851	54,696	50,115	53,939	49,383	50,853	225,325	204,290	12,842	12,392	13,171	15,036	16,831	12,321	12,076	10,289	8,738	3,082	0	56,264	22,109	77,104	71,058	71,879	75,363	73,282	66,172	66,772	60,404	62,677	52,465	50,853	281,589	226,399
Member benefit claims									4,642	4,409	466	0	0	0	0	0	0	0	0	0	0	0	0	0	1,157	1,098	1,303	1,288	945	1,309	867	278	211	(23)	0	4,409	466	1,157	1,098	1,303	1,288	945	1,309	867	278	211	(23)	0	4,409	466
Commissions									128,741	126,918	92,646	21,548	19,892	20,039	20,465	17,926	17,323	18,517	17,372	16,432	17,850	19,349	74,231	71,003	11,829	11,390	11,949	13,883	16,011	11,404	11,389	10,011	8,527	3,105	0	52,687	21,643	33,377	31,282	31,988	34,348	33,937	28,727	29,906	27,383	24,959	20,955	19,349	126,918	92,646
Total expenses	65,909	70,654	64,991	66,560	67,887	67,075	64,130	62,018	268,114		203,026	57,668	52,503	53,308	52,716	50,119	51,417	49,762	43,723	46,916	43,437	45,288	203,236	179,364	12,986	12,488	13,252	15,171	16,956	12,713	12,256	10,289	8,863	3,249	656	57,096	22,109	70,654	64,991	66,560	67,887	67,075	64,130	62,018	54,617	55,779	46,686	45,944	261,110	203,026
Net Income	$ 3,783	$ 4,024	$ 3,944	$ 3,414	$ 4,903	$ 3,997	$ 1,290	$ 3,319	$ 15,165	$ 13,509	$ 15,194	$ 4,110	$ 4,002	$ 3,463	$ 4,984	$ 4,072	$ 1,525	$ 3,427	$ 4,510	$ 4,447	$ 3,772	$ 3,474	$ 14,514	$ 16,203	$ (86)	$ (58)	$ (49)	$ (81)	$ (75)	$ (235)	$ (108)	$ 0	$ (81)	$ (109)	$ (426)	$ (499)	$ 0	$ 4,024	$ 3,944	$ 3,414	$ 4,903	$ 3,997	$ 1,290	$ 3,319	$ 4,117	$ 4,366	$ 3,663	$ 3,048	$ 13,509	$ 15,194
Basic	$ 0.19	$ 0.21	$ 0.20	$ 0.17	$ 0.24	$ 0.20	$ 0.06	$ 0.16	$ 0.77		$ 0.95	$ 0.21	$ 0.20	$ 0.17	$ 0.24	$ 0.20	$ 0	$ 0	$ 0.27	$ 0.28	$ 0	$ 0	$ 0.71	$ 1.02	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ (0.01)	$ (0.01)	$ 0.00	$ 0.00	$ (0.01)	$ (0.03)	$ (0.02)	$ 0.00	$ 0.21	$ 0.20	$ 0.17	$ 0.24	$ 0.20	$ 0	$ 0	$ 0.25	$ 0.28	$ 0	$ 0	$ 0.66	$ 0.95
Diluted	$ 0.18	$ 0.20	$ 0.19	$ 0.16	$ 0.24	$ 0.19	$ 0.06	$ 0.15	$ 0.74		$ 0.88	$ 0.20	$ 0.19	$ 0.17	$ 0.24	$ 0.19	$ 0	$ 0	$ 0.25	$ 0.26	$ 0	$ 0	$ 0.68	$ 0.94	$ 0.00	$ 0.00	$ (0.01)	$ 0.00	$ 0.00	$ (0.01)	$ (0.01)	$ 0.00	$ 0.00	$ (0.01)	$ (0.03)	$ (0.02)	$ 0.00	$ 0.20	$ 0.19	$ 0.16	$ 0.24	$ 0.19	$ 0	$ 0	$ 0.23	$ 0.26	$ 0	$ 0	$ 0.64	$ 0.88
Basic	19,507,733	19,531,694	19,705,276	19,904,819	20,343,038	20,404,441	20,510,254	20,464,592	19,655,492			19,531,694	19,705,276	19,904,819	20,343,038	20,404,441	20,510,254	20,464,592	16,483,626	15,742,336	15,742,336	15,742,336										16,483,626						19,531,694	19,705,276	19,904,819	20,343,038	20,404,441	20,510,254	20,464,592	16,483,626	15,742,336	15,742,336	15,742,336	20,352,027	15,929,181
Diluted	20,507,329	20,463,238	20,632,233	20,739,196	20,955,690	21,214,365	21,592,418	21,668,333	20,600,362			20,463,238	20,632,233	20,739,196	20,955,690	21,214,365	21,592,418	21,668,333	17,703,334	17,057,157	17,040,432	16,941,372										17,703,334						20,463,238	20,632,233	20,739,196	20,955,690	21,214,365	21,592,418	21,668,333	17,703,334	17,057,157	17,040,432	16,941,372	21,265,801	17,220,029