CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Tax benefit (expense) on change in retirement obligations, tax	$ 1.6	$ 4.2	$ 1.7
Tax benefit from change on derivatives designated as cash flow hedges, tax	$ 2.8	$ 12.5	$ 11.9
Issuance of common stock from issuance of unvested shares, exercise of stock options and deferred compensation plans, shares	1,826,977	1,596,145	1,222,274
Repurchase of common stock, shares	2,182,946
Cash dividends declared, per common share outstanding	$ 0.80	$ 0.68	$ 0.60