Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Stock-Based Compensation (Schedule of Weighted Average Assumptions for Restricted Stock Units) (Details)

v2.4.0.8
Stock-Based Compensation Stock-Based Compensation (Schedule of Weighted Average Assumptions for Restricted Stock Units) (Details) (Restricted Stock Units (RSUs) [Member], USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Restricted Stock Units (RSUs) [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 3 years 10 months 2 days 3 years 10 months 10 days 3 years 11 months 16 days
Expected dividend yield 1.58% 1.77% 1.33%
Estimated average fair value per restricted stock unit granted $ 53.34 $ 46.57 $ 58.37