XML 88 R72.htm IDEA: XBRL DOCUMENT v3.10.0.1
Earnings Per Share (Weighted-Average Shares of Common Stock Outstanding used in Calculation of Basic and Diluted Earnings Per Share) (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Earnings Per Share [Abstract]                      
Net income $ 57,152 $ 16,144 $ (57,392) $ 31,547 $ 7,660 $ 49,161 $ 9,233 $ 37,600 $ 47,451 $ 103,654 $ 76,238
Basic weighted-average shares outstanding                 114,909 119,860 124,448
Dilutive impact of stock options and restricted shares                 1,606 1,162 696
Diluted weighted-average shares outstanding                 116,515 121,022 125,144
Net income per common share:                      
Basic                 $ 0.41 $ 0.86 $ 0.61
Diluted                 $ 0.41 $ 0.86 $ 0.61