2013 | 2012 | 2011 | |||||||||
Accrued but unpaid additions to property and equipment at December 31 | $ | 49,220 | $ | 41,754 | $ | 66,764 | |||||
Cash interest payments in excess of interest capitalized | 65,824 | 44,579 | 14,802 | ||||||||
Net cash income tax payments (refunds) | (5,929 | ) | 13,150 | 276,839 |