Annual report pursuant to Section 13 and 15(d)

Earnings Per Share (Details)

v3.8.0.1
Earnings Per Share (Details) - shares
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Earnings Per Share [Abstract]      
Weighted Average Number of Shares Outstanding, Basic 82,308,417 83,112,012 85,378,480
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements 98,651 41,647 0
Weighted Average Number of Shares Outstanding, Diluted 82,407,068 83,153,659 85,378,480