CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, issued	78,554,965	78,124,668
Common stock, outstanding	78,554,965	78,124,668
Variable interest held by entity, assets	$ 4,005,933	$ 3,941,212
Variable interest held by entity, liabilities	$ 3,912,958	$ 3,838,386