CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY ( UNAUDITED ) (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Other comprehensive income (loss), net of tax:
Dividends: declared and paid (in dollars per share)	$ 0.36	$ 0.275
Exercise of employee stock options: shares issued (in shares)	2,544,948	554,360
Other stock-based compensation, net: shares issued (in shares)	314,000	249,068
Other stock-based compensation, net: shares repurchased (in shares)	91,350	212,012
Other stock-based compensation, net: shares forfeited (in shares)		4,467
Repurchase Class A Common shares (in shares)	10,133,969	8,870,598