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Share and Unit-Based Plans - Stock Options Narrative (Details) - Stock options - $ / shares
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2016
Jan. 06, 2016
Dec. 31, 2015
Dec. 09, 2015
Dec. 08, 2015
Dec. 31, 2014
Dec. 31, 2013
Share and unit-based plans                
Grant date of award (in dollars per share) $ 9.67              
Volatility rate (as a percent) 25.85%              
Dividend yield (as a percent) 3.69%              
Risk free rate (as a percent) 1.20%              
Current value (in dollars per share) $ 59.57              
Expected term (in years) 8 years              
Stock options, outstanding, number (shares)   10,565 10,565 10,314 10,314 10,068 10,068 10,068
Stock options, outstanding, weighted average exercise price (in dollars per share)   $ 56.77 $ 56.77 $ 58.15 $ 58.15 $ 59.57 $ 59.57 $ 59.57