| In millions, except per share items | Sep-30-16 | Jun-30-16 | Mar-31-16 | Dec-31-15 | Sep-30-15 | Jun-30-15 | Mar-31-15 | Dec-31-14 |
| | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q |
| Cash Flows From Operating Activities | | | | | | | | |
| Net loss | -1,476.5 | -1,918.8 | -3,413.2 | -4,069.0 | -3,034.4 | -2,433.8 | -786.6 | -284.3 |
| |
| Adjustments to reconcile net loss to net cash from (used in) operating activities: | | | | | | | | |
| Depreciation, depletion and amortization | 247.1 | 339.5 | 482.7 | 616.8 | 670.4 | 705.5 | 632.6 | 544.6 |
| Impairment of oil and natural gas properties | 1,995.7 | 2,813.6 | 4,523.2 | 4,752.3 | 3,326.6 | 2,421.9 | | |
| Gain on early extinguishment of debt | | | -1,525.6 | -748.6 | -458.3 | | | |
| Change in fair value of derivative financial instruments | | | 15.5 | 44.8 | -33.6 | -52.0 | | |
| Payment of interest in-kind | | | | | | | | |
| Accretion of asset retirement obligations | 69.3 | 64.7 | 58.1 | 55.2 | 52.0 | 50.1 | 47.1 | 41.0 |
| Loss from equity method investees | | | | | 28.9 | 17.2 | 2.7 | 1.1 |
| Amortization and write-off of debt issuance costs and other | 133.8 | 138.5 | 142.9 | 28.7 | 26.1 | 23.2 | 22.0 | 14.8 |
| Deferred rent | 1.7 | | | | 2.3 | | | |
| Stock-based compensation | 1.1 | 1.3 | 2.0 | 2.5 | 2.7 | 4.1 | 4.7 | 5.4 |
| Changes in operating assets and liabilities | | | | | | | | |
| Accounts receivable | 9.1 | 42.7 | 22.7 | 88.3 | 67.6 | 51.3 | 104.9 | 80.1 |
| Prepaid expenses and other current assets | -9.8 | -24.4 | 2.2 | 14.6 | 26.3 | 48.1 | 10.8 | 22.3 |
| Settlement of asset retirement obligations | -54.6 | -78.3 | -104.4 | -106.3 | -132.3 | -106.6 | -88.4 | -77.3 |
| Accounts payable and accrued liabilities | 7.2 | -62.2 | 77.3 | 2.1 | -185.2 | -113.1 | -324.3 | -181.2 |
| Net Cash Provided by (Used in) Operating Activities | -77.3 | -166.7 | -28.5 | 79.5 | 57.6 | 330.8 | 259.9 | 445.1 |
| |
| Cash Flows from Investing Activities | | | | | | | | |
| Acquisitions, net of cash | | | | -2.8 | -2.2 | | -814.9 | |
| Capital expenditures | -50.9 | -111.9 | -305.4 | -350.5 | -512.5 | -723.8 | -726.2 | -849.6 |
| Insurance payments received | | 8.3 | | 8.3 | 4.9 | 3.9 | | |
| Transfer to restricted cash | -22.2 | -22.1 | -37.9 | -28.4 | -14.7 | -14.7 | | 0.7 |
| Proceeds from the sale of properties | | 5.7 | | 259.6 | 258.8 | 261.9 | 131.6 | |
| Other | -0.1 | 0.0 | -0.3 | -0.2 | 0.1 | -0.1 | -0.3 | 0.3 |
| Net Cash Used in Investing Activities | -64.6 | -122.9 | -81.2 | -113.9 | -254.3 | -460.4 | -1,414.7 | -1,562.4 |
| |
| Cash Flows from Financing Activities | | | | | | | | |
| Proceeds from the issuance of common and preferred stock, net of offering costs | | | 0.5 | 0.6 | 0.4 | 2.3 | 2.3 | 2.6 |
| Dividends to shareholders - preferred | | | | -11.4 | -11.5 | -11.5 | -11.5 | -11.5 |
| Payments on long-term debt | | | -246.4 | -1,213.0 | -1,393.6 | -1,747.8 | -2,417.5 | -1,711.5 |
| Payment of debt assumed in acquisition | | | -271.6 | -1,238.2 | -1,418.8 | -1,747.8 | -2,417.5 | -1,711.5 |
| |
| Fees related to debt extinguishment | | | | | | | | |
| Debt issuance costs | -2.2 | | -3.8 | -41.7 | -41.1 | -43.4 | -56.0 | -16.8 |
| Other | | | -1.1 | | -1.1 | -0.1 | | |
| Net Cash Used in Financing Activities | -133.9 | | -308.9 | 259.0 | 568.7 | 740.7 | 1,453.2 | 860.8 |
| |
| Net Increase (Decrease) in Cash and Cash Equivalents | -275.7 | -553.6 | -418.6 | 224.6 | 372.0 | 611.0 | 298.3 | -256.5 |
| Cash and Cash Equivalents, beginning of period | 203.3 | | | | 756.8 | | | |
| Cash and Cash Equivalents, end of period | -72.5 | 203.3 | 338.3 | 981.5 | 1,128.8 | 756.8 | 444.1 | -110.7 |