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Condensed Statements of Operations and Comprehensive Income (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 |  |  |  |  |  |  |  |  |  |  |
Gain on sale of investments |  |  |  |  |  |  |  |  | $ (660) | $ (1,463) | $ 19
Expenses |  |  |  |  |  |  |  |  |  |  |
Compensation and employee benefits |  |  |  |  |  |  |  |  | 160,506 | 151,697 | 134,382
Other operating expenses |  |  |  |  |  |  |  |  | 47,045 | 47,570 | 45,047
Total expenses | $ 68,366 | $ 68,552 | $ 65,309 | $ 63,344 | $ 66,717 | $ 65,180 | $ 64,461 | $ 62,356 | 265,571 | 258,714 | 236,757
Income tax benefit | (31,327) | (11,639) | (11,905) | (9,754) | (9,662) | (10,156) | (10,492) | (9,352) | (64,625) | (39,662) | (33,999)
Net Income | $ 14,956 | $ 36,479 | $ 33,687 | $ 31,255 | $ 31,041 | $ 30,957 | $ 30,451 | $ 28,682 | 116,377 | 121,131 | 116,127
Comprehensive Income |  |  |  |  |  |  |  |  | 122,131 | 111,760 | 100,372
Parent Company |  |  |  |  |  |  |  |  |  |  |
Income |  |  |  |  |  |  |  |  |  |  |
Dividends from subsidiaries |  |  |  |  |  |  |  |  | 119,000 | 108,350 | 109,000
Gain on sale of investments |  |  |  |  |  |  |  |  | 3 | 0 | 0
Intercompany charges for services |  |  |  |  |  |  |  |  | 14,299 | 12,248 | 10,562
Other income |  |  |  |  |  |  |  |  | 225 | 311 | 196
Total income |  |  |  |  |  |  |  |  | 133,527 | 120,909 | 119,758
Expenses |  |  |  |  |  |  |  |  |  |  |
Compensation and employee benefits |  |  |  |  |  |  |  |  | 17,864 | 15,665 | 13,205
Other operating expenses |  |  |  |  |  |  |  |  | 10,425 | 7,701 | 7,313
Total expenses |  |  |  |  |  |  |  |  | 28,289 | 23,366 | 20,518
Income before income tax benefit and equity in undistributed net income of subsidiaries |  |  |  |  |  |  |  |  | 105,238 | 97,543 | 99,240
Income tax benefit |  |  |  |  |  |  |  |  | 2,983 | 4,040 | 3,105
Income before equity in undistributed net income of subsidiaries |  |  |  |  |  |  |  |  | 108,221 | 101,583 | 102,345
Equity in undistributed net income of subsidiaries |  |  |  |  |  |  |  |  | 8,156 | 19,548 | 13,782
Net Income |  |  |  |  |  |  |  |  | 116,377 | 121,131 | 116,127
Comprehensive Income |  |  |  |  |  |  |  |  | $ 122,131 | $ 111,760 | $ 100,372

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