Quarterly report pursuant to Section 13 or 15(d)

Consolidated Balance Sheets (Unaudited) (Parenthetical)

v3.8.0.1
Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Statement of Financial Position [Abstract]    
Capitalized costs of oil and natural gas properties excluded from amortization $ 2,971,119 $ 2,912,974
Preferred stock, par value (in usd per share) $ 0.01 $ 0.01
Preferred stock, shares authorized (in shares) 5,000,000 5,000,000
Preferred stock dividend rate, percent 12.00% 12.00%
Redeemable preferred stock, shares authorized (in shares) 30,000 30,000
Preferred stock Series A, issued (in shares) 0 0
Preferred stock Series A, outstanding (in shares) 0 0
Common stock, par value (in usd per share) $ 0.01 $ 0.01
Common stock, shares authorized (in shares) 200,000,000 200,000,000
Common stock, shares, issued (in shares) 173,523,487 183,105,910
Common stock, shares, outstanding (in shares) 173,523,487 183,105,910