| 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 | -131.1 | -195.6 | 160.8 | -1,310.6 | -573.4 | -1,690.0 | -495.1 | -276.0 |
| |
| Adjustments to reconcile net loss to net cash from (used in) operating activities: | | | | | | | | |
| Depreciation, depletion and amortization | 31.6 | 40.1 | 53.8 | 121.6 | 124.0 | 183.3 | 187.9 | 175.2 |
| Impairment of oil and natural gas properties | 86.8 | 142.6 | 340.5 | 1,425.8 | 904.7 | 1,852.3 | 569.6 | |
| Gain on early extinguishment of debt | | | -777.0 | -290.3 | -458.3 | | | |
| Change in fair value of derivative financial instruments | | | 61.3 | -42.2 | -36.7 | 33.1 | 90.6 | -120.6 |
| Payment of interest in-kind | | | | | | | | |
| Accretion of asset retirement obligations | 19.4 | 18.9 | 15.1 | 15.9 | 14.8 | 12.4 | 12.1 | 12.8 |
| Loss from equity method investees | | | | | 10.7 | 14.2 | 2.6 | 1.3 |
| Amortization and write-off of debt issuance costs and other | 0.9 | 0.9 | 126.5 | 5.5 | 5.6 | 5.3 | 12.3 | 2.9 |
| Deferred rent | 1.7 | | | | 2.3 | | | |
| Stock-based compensation | 0.1 | 0.2 | 0.2 | 0.6 | 0.4 | 0.9 | 0.6 | 0.9 |
| Changes in operating assets and liabilities | | | | | | | | |
| Accounts receivable | 6.0 | 9.1 | -37.3 | 31.3 | 39.6 | -10.9 | 28.3 | 10.5 |
| Prepaid expenses and other current assets | 0.5 | -11.5 | -1.9 | 3.1 | -14.1 | 15.1 | 10.5 | 14.8 |
| Settlement of asset retirement obligations | -17.0 | -3.2 | -21.3 | -13.1 | -40.6 | -29.3 | -23.3 | -39.1 |
| Accounts payable and accrued liabilities | 21.2 | 25.3 | -31.9 | -7.4 | -48.2 | 164.8 | -107.1 | -194.6 |
| Net Cash Provided by (Used in) Operating Activities | 20.2 | 32.2 | -109.0 | -20.7 | -69.2 | 170.4 | -1.0 | -42.6 |
| |
| Cash Flows from Investing Activities | | | | | | | | |
| Acquisitions, net of cash | | | | -0.6 | -2.2 | | 0.0 | |
| Capital expenditures | -7.7 | -18.1 | -18.0 | -7.1 | -68.7 | -211.5 | -63.2 | -169.1 |
| Insurance payments received | | 3.9 | | 3.4 | 1.0 | 1.3 | 2.7 | |
| Transfer to restricted cash | 0.0 | 0.8 | -9.5 | -13.3 | 0.0 | -15.0 | | 0.3 |
| Proceeds from the sale of properties | | 1.1 | | 0.8 | 3.8 | 254.8 | 0.1 | |
| Other | 0.1 | -0.1 | 0.0 | -0.1 | 0.1 | -0.3 | 0.1 | 0.2 |
| Net Cash Used in Investing Activities | -7.7 | -12.4 | -27.6 | -16.9 | -66.0 | 29.2 | -60.3 | -157.2 |
| |
| Cash Flows from Financing Activities | | | | | | | | |
| Proceeds from the issuance of common and preferred stock, net of offering costs | | | 0.0 | 0.0 | 0.3 | 0.1 | 0.1 | -0.2 |
| Dividends to shareholders - preferred | | | | -2.8 | -2.9 | -2.9 | -2.9 | -2.9 |
| Payments on long-term debt | | | -2.9 | -125.2 | -99.8 | -18.5 | -969.5 | -305.8 |
| Payment of debt assumed in acquisition | | | -2.9 | -125.2 | -125.0 | -18.5 | -969.5 | -305.8 |
| |
| Fees related to debt extinguishment | | | | | | | | |
| Debt issuance costs | 0.0 | | -1.5 | -0.6 | 0.0 | -1.6 | -39.4 | -0.1 |
| Other | | | 0.0 | | -1.0 | -0.1 | | 0.0 |
| Net Cash Used in Financing Activities | 0.0 | | -5.9 | -128.0 | -130.1 | -44.8 | 562.0 | 181.7 |
| |
| Net Increase (Decrease) in Cash and Cash Equivalents | 12.5 | 19.8 | -142.4 | -165.6 | -265.4 | 154.8 | 500.7 | -18.2 |
| Cash and Cash Equivalents, beginning of period | 203.3 | | | | 756.8 | | | |
| Cash and Cash Equivalents, end of period | 215.7 | 19.8 | -142.4 | -165.6 | 491.5 | 154.8 | 500.7 | -18.2 |