Note 13 - Selected Quarterly Financial Data (Unaudited) (Details) - Selected Quarterly Financial Data (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Selected Quarterly Financial Data [Abstract]
Revenue (less agency commissions)	$ 95,556	$ 88,288	$ 84,285	$ 78,169	$ 126,587	$ 102,879	$ 94,691	$ 80,674	$ 346,298	$ 404,831	$ 307,131
Operating income	23,288	24,220	21,312	15,060	58,511	41,063	33,046	20,821	83,880	153,441	75,348
Net income	5,201	7,073	5,144	870	(2,109)	15,873	10,994	3,371	18,288	28,129	9,035
Net income available to common stockholders	$ 5,201	$ 7,073	$ 5,144	$ 870	$ (2,613)	$ 14,640	$ 9,815	$ 2,192	$ 18,288	$ 24,034	$ 1,795
Basic net income per share available to common stockholders (in Dollars per share)	$ 0.09	$ 0.12	$ 0.09	$ 0.02	$ (0.05)	$ 0.26	$ 0.17	$ 0.04	$ 0.32	$ 0.42	$ 0.03
Diluted net income per share available to common stockholders (in Dollars per share)	$ 0.09	$ 0.12	$ 0.09	$ 0.02	$ (0.05)	$ 0.26	$ 0.17	$ 0.04	$ 0.32	$ 0.42	$ 0.03