CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
CONSOLIDATED BALANCE SHEETS
INVESTMENTS, fair value (in dollars)	$ 505,800	$ 155,808
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	2,500,000	2,500,000
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	81,290,845	79,091,532
Common stock, shares outstanding	77,921,064	75,722,274
Treasury stock, shares	3,369,781	3,369,258