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v3.3.1.900

Subsequent Events - Additional Information (Detail) |  |  |  | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Feb. 02, 2016 USD ($) $ / shares shares | Mar. 09, 2015 USD ($) $ / shares shares | Dec. 09, 2013 $ / shares shares | Dec. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Dec. 31, 2013 USD ($) | Feb. 23, 2016 USD ($) | Feb. 22, 2016 USD ($) | Feb. 18, 2016 MBbls $ / bbl
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Shares issued, price per share (in usd per share) | $ / shares |  | $ 12.80 | $ 44.94 |  |  |  |  |  |
Proceeds from sale of common stock | $ |  | $ 462,800,000 |  | $ 462,833,000 | $ 0 | $ 314,580,000 |  |  |
Unsecured debt | Line of credit | Consent Notes |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Current borrowing base | $ |  |  |  | $ 1,525,000,000.0 |  |  |  |  |
Common stock |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Issuance of common stock, shares | shares |  | 36,800,000 | 7,000,000 |  |  |  |  |  |
Common stock | Underwriters' option |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Issuance of common stock, shares | shares |  | 4,800,000 |  |  |  |  |  |  |
Subsequent event |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Weighted average floor price (in dollars per barrel) | $ / bbl |  |  |  |  |  |  |  |  | 41.58
Shares issued, price per share (in usd per share) | $ / shares | $ 4.685 |  |  |  |  |  |  |  |
Proceeds from sale of common stock | $ | $ 182,900,000 |  |  |  |  |  |  |  |
Subsequent event | Unsecured debt | Line of credit | Consent Notes |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Current borrowing base | $ |  |  |  |  |  |  | $ 1,150,000,000.0 | $ 1,525,000,000.0 |
Subsequent event | Common stock |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Issuance of common stock, shares | shares | 39,100,000 |  |  |  |  |  |  |  |
Subsequent event | Common stock | Underwriters' option |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Issuance of common stock, shares | shares | 5,100,000 |  |  |  |  |  |  |  |
Subsequent event | 2016 Swaps | Not designated as hedging instrument |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Total notional amount of oil barrels | MBbls |  |  |  |  |  |  |  |  | 1,131
Subsequent event | 2017 Swaps | Not designated as hedging instrument |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Total notional amount of oil barrels | MBbls |  |  |  |  |  |  |  |  | 2,159
Subsequent event | 2018 Swaps | Not designated as hedging instrument |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |
Total notional amount of oil barrels | MBbls |  |  |  |  |  |  |  |  | 186,000

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- Definition Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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