v2.4.0.6
CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
Sep. 30, 2012
Dec. 31, 2011
Other property and equipment, accumulated depreciation (in dollars) $ 20,821,000 $ 10,714,000
Common stock, par value (in dollars per share) $ 0.01 $ 0.01
Common stock, authorized shares 200,000,000 200,000,000
Common stock, issued shares 66,121,809 64,145,482
Common stock, outstanding, net of treasury shares 66,071,228 64,064,415
Treasury stock, shares 50,581 81,067
Convertible Debt [Member]
    
Debt Instrument, Unamortized Discount $ 0 $ 2,431,000
Interest rate on notes (as a percent) 3.50% 3.50%
6.625% Senior Notes [Member]
    
Interest rate on notes (as a percent) 6.625% 6.625%
6.50% Senior Notes [Member]
    
Interest rate on notes (as a percent) 6.50% 6.50%
6.50% Senior Notes due 2023 [Member]
    
Interest rate on notes (as a percent) 6.50%