XML 105 R89.htm IDEA: XBRL DOCUMENT v3.6.0.2
Common Stock and Earnings Per Share - Additional Information (Details) - $ / shares
12 Months Ended
Mar. 11, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Aug. 05, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]          
Antidilutive potentially securities   85,500 60,200 40,400  
Additional diluted outstanding shares   0      
4.50% Convertible Senior Notes due 2020 [Member]          
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]          
Debt instrument interest rate 4.50% 4.50%      
Debt Instrument Maturity Year 2020 2020 2020    
Conversion price per share $ 68.90 $ 68.90     $ 68.84