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Condensed Consolidated Statements of Changes in Capital (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017 | Dec. 31, 2016
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Beginning Balance |  |  |  | $ 1,594,795 | $ 1,798,702 |  |
Common shares issued for compensation and effect of shares reissued to stock purchase plan |  |  |  | 1,314 | 1,878 |  |
Share-based compensation |  |  |  | 2,479 | 6,092 |  |
Net effect of restricted and performance shares issued |  |  |  | (3,869) | (5,323) |  |
Dividends to shareholders |  |  |  | (34,246) | (33,040) |  |
Other comprehensive income (loss) |  |  |  | (34,470) | 8,665 |  |
Net income |  | $ 28,423 | $ 19,518 | 40,279 | 60,973 |  |
Ending Balance |  | 1,574,616 | 1,838,096 | 1,574,616 | 1,838,096 |  |
Accounting Standards Update 2016-01 |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Cumulative-effect adjustment adoption of ASU | [1] |  |  |  |  | $ 8,334 |
Accounting Standards Update 2018-02 |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Cumulative-effect adjustment adoption of ASU | [1] |  |  |  |  | 0 |
Accounting Standards Update 2016-09 |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Cumulative-effect adjustment adoption of ASU | [1] |  |  |  |  |  | $ 149
Common Stock |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Beginning Balance |  |  |  | 628 | 627 |  |
Net effect of restricted and performance shares issued |  |  |  | 2 | 1 |  |
Ending Balance |  | 630 | 628 | 630 | 628 |  |
Additional Paid-in Capital |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Beginning Balance |  |  |  | 383,077 | 376,518 |  |
Common shares issued for compensation and effect of shares reissued to stock purchase plan |  |  |  | 1,316 | 1,876 |  |
Share-based compensation |  |  |  | 2,479 | 6,092 |  |
Net effect of restricted and performance shares issued |  |  |  | (3,871) | (5,324) |  |
Ending Balance |  | 383,001 | 379,587 | 383,001 | 379,587 |  |
Additional Paid-in Capital | Accounting Standards Update 2016-09 |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Cumulative-effect adjustment adoption of ASU | [1] |  |  |  |  |  | 425
Accumulated Other Comprehensive Income (Loss) |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Beginning Balance |  |  |  | 14,911 | 17,399 |  |
Other comprehensive income (loss) |  |  |  | (34,470) | 8,665 |  |
Ending Balance |  | (16,143) | 26,064 | (16,143) | 26,064 |  |
Accumulated Other Comprehensive Income (Loss) | Accounting Standards Update 2018-02 |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Cumulative-effect adjustment adoption of ASU | [1] |  |  |  |  | 3,416 |
Retained Earnings |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Beginning Balance |  |  |  | 1,614,186 | 1,824,088 |  |
Dividends to shareholders |  |  |  | (34,246) | (33,040) |  |
Net income |  |  |  | 40,279 | 60,973 |  |
Ending Balance |  | 1,625,137 | 1,851,745 | 1,625,137 | 1,851,745 |  |
Retained Earnings | Accounting Standards Update 2016-01 |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Cumulative-effect adjustment adoption of ASU | [1] |  |  |  |  | 8,334 |
Retained Earnings | Accounting Standards Update 2018-02 |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Cumulative-effect adjustment adoption of ASU | [1] |  |  |  |  | $ (3,416) |
Retained Earnings | Accounting Standards Update 2016-09 |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Cumulative-effect adjustment adoption of ASU | [1] |  |  |  |  |  | $ (276)
Treasury Stock |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity: |  |  |  |  |  |  |
Beginning Balance |  |  |  | (418,007) | (419,930) |  |
Common shares issued for compensation and effect of shares reissued to stock purchase plan |  |  |  | (2) | 2 |  |
Ending Balance |  | $ (418,009) | $ (419,928) | $ (418,009) | $ (419,928) |  |
[1] | See Note 1 for discussion of accounting guidance adopted during the period.

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