Stock-Based Compensation Plans (Details 2) (Restricted Stock, USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested restricted stock balance, number of shares	417,464		551,678
Granted in 2013, number of shares	27,561		263,771	297,859
Vested in 2013, number of shares	167,751	[1]
Nonvested restricted stock balance, weighted average grant-date fair value (in dollars per share)	$ 45.46		$ 46.73
Granted in 2013, weighted average grant-date fair value (in dollars per share)	$ 42.53		$ 44.82	$ 38.44
Vested in 2013, weighted average grant-date fair value (in dollars per share)	$ 37.10
Dividend shares earned during period, number of shares	23,446

[1] Includes 23,446 shares for dividends earned during vesting period