Stock Based Compensation - Assumptions Used To Determine Fair Value of Stock Options (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Grant date fair value	$ 5.59	$ 4.42	$ 4.01
Expected life of options	8 years	8 years	8 years
Risk-free interest rate	2.30%	1.30%	1.40%
Dividend yield rate	2.90%	2.80%	2.83%
Price volatility	28.89%	28.51%	28.56%