XML 82 R69.htm IDEA: XBRL DOCUMENT v3.8.0.1
Comprehensive Income (Components of Comprehensive Income-Gross and Net of Tax) (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income before federal income tax $ 68,150 $ 67,315 $ 58,929 $ 67,574 $ 50,326 $ 55,443 $ 62,311 $ 51,875 $ 261,968 $ 219,955 $ 232,692
Income Tax Expense (Benefit)                 93,142 61,460 66,831
Net income $ 30,242 $ 46,718 $ 41,426 $ 50,440 $ 39,360 $ 38,502 $ 43,601 $ 37,032 168,826 158,495 165,861
Unrealized holding gains (losses) during the period, Gross                 66,894 (9,195) (40,221)
Unrealized holding gains (losses) during the period, Tax                 23,879 (3,218) (14,078)
Unrealized holding gains (losses) arising during period, Net                 43,015 (5,977) (26,143)
Non-credit portion of other-than-temporary impairment losses recognized in other comprehensive income, Gross                 36 (10)  
Non-Credit Portion of Other-Than-Temporary Impairment Losses Recognized In Other Comprehensive Income, Tax                 13 (4)  
Non-credit portion of other-than-temporary impairments recognized in other comprehensive income, Net                 23 (6)  
Amount reclassified into net income: HTM securities, Gross                 (179) (141) (580)
Amounts reclassified into net income: HTM securities, Tax                 (63) (49) (203)
Amount reclassified into net income: HTM securities, Net                 (116) (92) (377)
Non-credit OTTI, Gross                 104 213 357
Non-credit OTTI, Tax                 36 75 125
Amounts reclassified into net income: Non-credit other-than-temporary impairment                 68 138 232
Realized (gains) losses on AFS securities, Gross                 (6,979) 4,713 (14,016)
Realized (gains) losses on AFS securities, Tax                 (2,442) 1,649 (4,906)
Realized (gains) losses on available for sale securities                 (4,537) 3,064 (9,110)
Net unrealized gains (losses), Gross                 59,876 (4,420) (54,460)
Net unrealized gains (losses), Tax                 21,423 (1,547) (19,062)
Total unrealized gains (losses) on investment securities                 38,453 (2,873) (35,398)
Net actuarial (loss) gain, Gross                 (4,684) (12,079) 2,438
Net actuarial (loss) gain, Tax                 (984) (4,227) 853
Net actuarial (loss) gain, Net                 (3,700) (7,852) 1,585
Amount reclassified into net i ncome: Net actuarial loss, Gross                 2,102 6,462 7,077
Amount reclassified into Net Income: Net actuarial loss, Tax                 735 2,262 2,477
Amount reclassified into net income: Net actuarial loss, Net                 1,367 4,200 4,600
Defined pension and other post-retirement benefit plans, Gross                 (2,582) (5,617) 9,515
Defined pension and other post-retirement benefit plans, Tax                 (249) (1,965) 3,330
Total defined benefit pension and post-retirement plans                 (2,333) (3,652) 6,185
Other Comprehensive Income (Loss), Gross                 57,294 (10,037) (44,945)
Other Comprehensive Income (Loss), Tax                 21,174 (3,512) (15,732)
Other comprehensive income (loss)                 36,120 (6,525) (29,213)
Comprehensive Income, Before Tax                 319,262 209,918 187,747
Comprehensive Income, Tax                 114,316 57,948 51,099
Comprehensive income                 $ 204,946 $ 151,970 $ 136,648