| Shareholders' Equity Activity Summarization [Table] |
| | | | | | | | Noncontrolling | | | | | Total | | | Company | | | interest in | | | | | shareholders' | | | shareholders' | | | consolidated | | Millions of dollars | | equity | | | equity | | | subsidiaries | | Balance at December 31, 2010 | | $ | 10,387 | | | $ | 10,373 | | | $ | 14 | | Transactions with shareholders | | | 181 | | | | 181 | | | | - | | Comprehensive income: | | | | | | | | | | | | | Net income | | | 1,252 | | | | 1,250 | | | | 2 | | Other comprehensive income | | | 3 | | | | 3 | | | | - | | Total comprehensive income | | | 1,255 | | | | 1,253 | | | | 2 | | Payments of dividends to shareholders | | | (165 | ) | | | (165 | ) | | | - | | | Balance at June 30, 2011 | | $ | 11,658 | | | $ | 11,642 | | | $ | 16 | |
| | | | | | | | | Noncontrolling | | | | | Total | | | Company | | | interest in | | | | | shareholders' | | | shareholders' | | | consolidated | | Millions of dollars | | equity | | | equity | | | subsidiaries | | Balance at December 31, 2009 | | $ | 8,757 | | | $ | 8,728 | | | $ | 29 | | Transactions with shareholders | | | 96 | | | | 98 | | | | (2 | ) | Comprehensive income: | | | | | | | | | | | | | Net income | | | 690 | | | | 686 | | | | 4 | | Other comprehensive income | | | 4 | | | | 4 | | | | - | | Total comprehensive income | | | 694 | | | | 690 | | | | 4 | | Payments of dividends to shareholders | | | (163 | ) | | | (163 | ) | | | - | | | Balance at June 30, 2010 | | $ | 9,384 | | | $ | 9,353 | | | $ | 31 | |
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