Shareholders' Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified				12 Months Ended		3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 2012 Common Stock Repurchase Program [Member]	Sep. 30, 2013 2012 Common Stock Repurchase Program [Member]	Sep. 30, 2012 2011 Common Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, shares of common stock approved for repurchase					250,000	500,000
Stock Repurchase Program, Number of Shares Repurchased				68,145
Share Repurchase Program, Shares Repurchased as Percentage of Shares Outstanding				1.00%
Stock repurchase program, expiration date						Oct. 01, 2013
Shares repurchased, average cost per share				$ 40.78
The percentage of the stock repurchase program's allotment repurchased during the period				27.00%
Dividends declared to shareholders	$ 8.3	$ 7.7	$ 11.5