Shareholders' Equity (Tables)

6 Months Ended

Jun. 30, 2012

Stockholders' Equity Note [Abstract]

Summary of shareholders' equity activity

The following tables summarize our shareholders’ equity activity.

Millions of dollars	Total Shareholders' equity			Company shareholders' equity			Noncontrolling interest in consolidated subsidiaries
Balance at December 31, 2011	$	13,216		$	13,198		$	18
Transactions with shareholders	131			133			(2		)
Comprehensive income	1,381			1,376			5
Payments of dividends to shareholders	(167		)	(167		)	—
Balance at June 30, 2012	$	14,561		$	14,540		$	21

Millions of dollars	Total Shareholders' equity			Company shareholders' equity			Noncontrolling interest in consolidated subsidiaries
Balance at December 31, 2010	$	10,387		$	10,373		$	14
Transactions with shareholders	181			181			—
Comprehensive income	1,255			1,253			2
Payments of dividends to shareholders	(165		)	(165		)	—
Balance at June 30, 2011	$	11,658		$	11,642		$	16

Schedule of comprehensive income (loss)

Accumulated other comprehensive loss consisted of the following:

Millions of dollars	June 30, 2012			December 31, 2011
Defined benefit and other postretirement liability adjustments	$	(194	)	$	(208	)
Cumulative translation adjustments	(67		)	(66		)
Unrealized gains on investments	—			1
Total accumulated other comprehensive loss	$	(261	)	$	(273	)