Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation (Summary Of The Changes In The Number Of Outstanding Phantom Stock Shares) (Details) [Axis]

v3.6.0.2
Share-Based Compensation (Summary Of The Changes In The Number Of Outstanding Phantom Stock Shares) (Details) [Axis]
12 Months Ended
Dec. 31, 2016
shares
Employee Phantom Stock Plan [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Balance of shares outstanding at December 31, 2014 519,351
Granted 0
Settled (1,658)
Forfeited 0
Balance of shares outstanding at December 31, 2015 517,693
Director Phantom Stock Plan [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Balance of shares outstanding at December 31, 2014 82,253
Granted 0
Settled 14,091
Forfeited 0
Balance of shares outstanding at December 31, 2015 68,162
Phantom Shares [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Balance of shares outstanding at December 31, 2014 601,604
Granted 0
Settled (15,749)
Forfeited 0
Balance of shares outstanding at December 31, 2015 585,855