CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (UNAUDITED) (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Issuance of common stock (in shares)	44,352	136,419
Purchase of common stock (in shares)		255,377
Dividends paid on common stock (in dollars per shares)	$ 0.52	$ 0.51