Consolidated Statements of Equity (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash dividends declared per share	$ 1.98	$ 1.80	$ 1.64
Tax effect on stock options exercised	$ (11,018)	$ (5,356)	$ (3,251)
Common Stock [Member]
Tax effect on stock options exercised	(11,018)	(5,356)	(3,251)
Additional Paid-In Capital [Member]
Tax effect on stock options exercised	(11,018)	(5,356)	(3,251)
Retained Earnings [Member]
Cash dividends declared per share	$ 1.98	$ 1.80	$ 1.64
Total Parent Equity [Member]
Cash dividends declared per share	$ 1.98	$ 1.80	$ 1.64
Tax effect on stock options exercised	$ (11,018)	$ (5,356)	$ (3,251)