CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS)/INCOME [Abstract]
Net (loss)/income	$ (26,125)	$ 24,360	$ 16,484
Other comprehensive (loss)/income:
Unrealized gains on investments, net of tax expense of $15, $112 and $305, in 2012, 2011 and 2010, respectively	25	182	500
Reclassification of realized gains on sales of investments to earnings, net of tax expense of $(95) and $(309) in 2012 and 2011, respectively	(162)	(502)	0
Unrealized gains/losses on swap derivatives, net of tax expense of $105 in 2010	0	0	170
Reclassifications of net losses on swap derivatives to earnings, net of tax benefit of $(349) in 2011	0	571	0
Other-than-temporary loss on investments, net of tax benefit of $765 in 2010	0	0	1,247
Total comprehensive (loss)/income	$ (26,262)	$ 24,611	$ 18,401