| | Three Months Ended
December 31, | | Year Ended
December 31, | |
| | 2013 | | 2012 | | 2013 | | 2012 | |
CASH FLOWS FROM OPERATING ACTIVITIES | | | | | | | | | |
Net income (loss) | | $ | 6,425 | | $ | 1,678 | | $ | (24,862 | ) | $ | 35,103 | |
Adjustments to reconcile net income (loss) to cash provided by operating activities: | | | | | | | | | |
Depreciation, depletion and amortization | | 41,039 | | 39,201 | | 150,902 | | 142,687 | |
Impairment of property and equipment | | — | | 233 | | 89,811 | | 5,944 | |
Exploration costs | | 2,907 | | 1,930 | | 5,887 | | 4,222 | |
Gain on sales of assets and impairment of inventory, net | | (1,497 | ) | (405 | ) | (3,024 | ) | (463 | ) |
Deferred income tax expense (benefit) | | 4,651 | | 3,450 | | (14,042 | ) | 22,008 | |
Non-cash employee compensation | | 2,404 | | (2,604 | ) | (3,493 | ) | (404 | ) |
(Gain) loss on derivatives | | (1,188 | ) | (4,592 | ) | 8,731 | | (14,448 | ) |
Cash settlements of derivatives | | 2,054 | | 1,551 | | 690 | | (3,410 | ) |
Accretion of asset retirement obligations | | 1,034 | | 1,068 | | 4,203 | | 3,696 | |
Amortization of debt issue costs and original issue discount | | 985 | | 967 | | 3,266 | | 2,554 | |
Amortization of deferred revenue from volumetric production payment | | (2,107 | ) | (2,433 | ) | (8,746 | ) | (8,295 | ) |
Changes in operating working capital: | | | | | | | | | |
Accounts receivable | | (6,975 | ) | 149 | | (7,163 | ) | 7,299 | |
Accounts payable | | 16,800 | | (3,614 | ) | 12,740 | | (9,386 | ) |
Other | | 163 | | (5,240 | ) | 5,676 | | 2,115 | |
Net cash provided by operating activities | | 66,695 | | 31,339 | | 220,576 | | 189,222 | |
CASH FLOWS FROM INVESTING ACTIVITIES | | | | | | | | | |
Additions to property and equipment | | (80,111 | ) | (88,039 | ) | (288,133 | ) | (526,521 | ) |
Proceeds from volumetric production payment | | 298 | | 447 | | 1,332 | | 45,479 | |
Proceeds from sales of assets | | 61,858 | | 2,911 | | 259,799 | | 3,778 | |
(Increase) decrease in equipment inventory | | (6,544 | ) | 1,249 | | (726 | ) | 1,313 | |
Other | | (146 | ) | 113 | | (1,315 | ) | (82 | ) |
Net cash used in investing activities | | (24,645 | ) | (83,319 | ) | (29,043 | ) | (476,033 | ) |
CASH FLOWS FROM FINANCING ACTIVITIES | | | | | | | | | |
Proceeds from long-term debt | | 225,335 | | 40,000 | | 268,335 | | 280,000 | |
Repayments of long-term debt | | (264,000 | ) | — | | (444,000 | ) | — | |
Proceeds from exercise of stock options | | 29 | | 12 | | 29 | | 12 | |
Net cash provided by (used in) financing activities | | (38,636 | ) | 40,012 | | (175,636 | ) | 280,012 | |
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS | | 3,414 | | (11,968 | ) | 15,897 | | (6,799 | ) |
CASH AND CASH EQUIVALENTS | | | | | | | | | |
Beginning of period | | 23,209 | | 22,694 | | 10,726 | | 17,525 | |
End of period | | $ | 26,623 | | $ | 10,726 | | $ | 26,623 | | $ | 10,726 | |
