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Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands | Total | Preferred Stock [Member] | Common Stock [Member] | Retained Earnings [Member] | Accumulated Other Comprehensive Income [Member]
--- | --- | --- | --- | --- | ---
Balance, value at Dec. 31, 2015 | $ 1,242,128 | $ 2,217 | $ 990,281 | $ 255,925 | $ (6,295)
Balance (in shares) at Dec. 31, 2015 |  | 9,000 | 57,724,000 |  |
Net income | 104,866 |  |  | 104,866 |
Other comprehensive income | (12,704) |  |  |  | (12,704)
Stock Adjustment Value Deferred Compensation | (11) |  |  |  |
Issuance of common stock - stock option and other plans, shares |  |  | 50,000 |  |
Issuance of common stock - stock option and other plans, value | 1,349 |  | $ 1,349 |  |
Issuance of common stock - restricted stock awards, net of canceled awards, shares |  |  | 306,000 |  |
Issuance of common stock - restricted stock awards, net of canceled awards, value | 5,009 |  | $ 5,009 |  |
Tax benefit deficiency associated with share-based compensation | 334 |  | $ 334 |  |
Purchase and retirement of common stock (in shares) |  |  | (38,000) |  |
Purchase and retirement of common stock, value | (1,125) |  | $ (1,125) |  |
Dividends, Preferred Stock, Cash | (157) |  |  | (157) |
Cash dividends paid on common stock | (88,677) |  |  | (88,677) |
Balance, value at Dec. 31, 2016 | $ 1,251,012 | $ 2,217 | $ 995,837 | 271,957 | (18,999)
Balance (in shares) at Dec. 31, 2016 |  | 9,000 | 58,042,000 |  |
Preferred Stock, Dividends, Per Share, Cash Paid | $ 1.53 |  |  |  |
Common Stock, Dividends, Per Share, Cash Paid | $ 1.53 |  |  |  |
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2016-09 [Member] | $ 67 |  | $ 184 | (117) |
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2018-02 [Member] | 0 |  |  | 4,082 | (4,082)
Net income | 112,828 |  |  | 112,828 |
Other comprehensive income | 856 |  |  |  | 856
Issuance of common stock, net of offering costs, shares |  |  | 14,642,000 |  |
Issuance of common stock, net of offering costs, value | 636,385 |  | $ 636,385 |  |
Stock Adjustment Value Deferred Compensation | 1 |  | $ 1 |  |
Issuance of common stock - stock option and other plans, shares |  |  | 49,000 |  |
Issuance of common stock - stock option and other plans, value | 1,980 |  | $ 1,980 |  |
Issuance of common stock - restricted stock awards, net of canceled awards, shares |  |  | 241,000 |  |
Issuance of common stock - restricted stock awards, net of canceled awards, value | 7,745 |  | $ 7,745 |  |
Conversion of Stock, Shares Converted |  | (9,000) |  |  |
Conversion of Stock, Amount Converted |  | $ (2,217) |  |  |
Conversion of Stock, Shares Issued |  |  | 102,000 |  |
Conversion of Stock, Amount Issued | 0 |  | $ 2,217 |  |
Purchase and retirement of common stock (in shares) |  |  | (56,000) |  |
Purchase and retirement of common stock, value | (2,299) |  | $ (2,299) |  |
Stock Redeemed or Called During Period, Value | (7,345) |  | (7,345) |  |
Cash dividends paid on common stock | (51,308) |  |  | (51,308) |
Balance, value at Dec. 31, 2017 | $ 1,949,922 | $ 0 | $ 1,634,705 | 337,442 | (22,225)
Balance (in shares) at Dec. 31, 2017 |  | 0 | 73,020,000 |  |
Preferred Stock, Dividends, Per Share, Cash Paid | $ 0.00 |  |  |  |
Common Stock, Dividends, Per Share, Cash Paid | $ 0.88 |  |  |  |
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2018-02 [Member] |  |  |  |  | (4,082)
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2016-01 [Member] | $ 0 |  |  | (157) | 157
Net income | 172,882 |  |  | 172,882 |
Other comprehensive income | (13,237) |  |  |  | (13,237)
Stock Adjustment Value Deferred Compensation | $ 7 |  | $ 7 |  |
Issuance of common stock - stock option and other plans, shares | 1,112 |  | 46,000 |  |
Issuance of common stock - stock option and other plans, value | $ 1,857 |  | $ 1,857 |  |
Issuance of common stock - restricted stock awards, net of canceled awards, shares |  |  | 246,000 |  |
Issuance of common stock - restricted stock awards, net of canceled awards, value | 8,354 |  | $ 8,354 |  |
Purchase and retirement of common stock (in shares) |  |  | (63,000) |  |
Purchase and retirement of common stock, value | (2,677) |  | $ (2,677) |  |
Cash dividends paid on common stock | (83,459) |  |  | (83,459) |
Balance, value at Dec. 31, 2018 | $ 2,033,649 | $ 0 | $ 1,642,246 | $ 426,708 | $ (35,305)
Balance (in shares) at Dec. 31, 2018 |  | 0 | 73,249,000 |  |
Preferred Stock, Dividends, Per Share, Cash Paid | $ 0.00 |  |  |  |
Common Stock, Dividends, Per Share, Cash Paid | $ 1.14 |  |  |  |

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