Annual report pursuant to Section 13 and 15(d)

Capital Structure and Per Share Data - Dilutive Effect on Earnings Per Share (Detail)

v3.6.0.2
Capital Structure and Per Share Data - Dilutive Effect on Earnings Per Share (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Earnings Per Share [Abstract]                      
Weighted Average Shares, Basic                 45,637 50,489 52,065
Weighted Average Shares, Stock compensation plans                 311 394 498
Weighted Average Shares, Diluted                 45,948 50,883 52,563
Income (Loss) From Continuing Operations, Amount                 $ 94,516 $ 88,091 $ 98,559
Participating securities income (loss) from continuing operations non-vested restricted stock and restricted stock units                 (52) (36) (311)
Income (Loss) From Continuing Operations, Basic, Amount                 94,464 88,055 98,248
Income (Loss) From Continuing Operations Diluted, Amount                 $ 94,464 $ 88,055 $ 98,248
Income (Loss) From Continuing Operations, Basic, Per Share Amount                 $ 2.07 $ 1.74 $ 1.89
Income (Loss) From Continuing Operations, Diluted, Per Share Amount                 $ 2.06 $ 1.73 $ 1.87
Dilutive effect on earnings per share                 $ (1,323) $ (1,780) $ (1,342)
Income (Loss) From Discontinued Operations, Basic earnings (loss), Amount                 (1,323) (1,780) (1,342)
Income (Loss) From Discontinued Operations, Diluted earnings (loss), Amount                 $ (1,323) $ (1,780) $ (1,342)
Income (Loss) From Discontinuing Operations, Basic earnings (loss), Per Share Amount                 $ (0.03) $ (0.03) $ (0.03)
Income (Loss) From Discontinued Operations, Diluted earnings (loss), Per Share Amount                 $ (0.03) $ (0.03) $ (0.03)
Net Income (Loss), Amount $ 37,636 $ 18,111 $ 22,822 $ 14,624 $ 31,058 $ 26,505 $ 14,781 $ 13,967 $ 93,193 $ 86,311 $ 97,217
Net Income (Loss), Basic, Amount                 93,141 86,275 96,906
Net Income (Loss), Diluted, Amount                 $ 93,141 $ 86,275 $ 96,906
Net Income (Loss), Basic, Per Share Amount $ 0.84 $ 0.40 $ 0.50 $ 0.31 $ 0.62 $ 0.53 $ 0.29 $ 0.27 $ 2.04 $ 1.71 $ 1.86
Net Income (Loss), Diluted, Per Share Amount $ 0.83 $ 0.40 $ 0.50 $ 0.31 $ 0.62 $ 0.52 $ 0.29 $ 0.27 $ 2.03 $ 1.70 $ 1.84