Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Preferred Stock [Member]
Balance, value at Dec. 31, 2013	$ 1,053,249us-gaap_StockholdersEquity	$ 860,562	$ 202,514	$ (12,044)	$ 2,217
Balance, shares at Dec. 31, 2013		51,265			9
Net Income	19,844us-gaap_NetIncomeLoss		19,844
Other comprehensive income	7,001			7,001
Issuance of common stock - cashless exercise of warrants, shares		1,140
Issuance of common stock - cashless exercise of warrants, value	0	0
Issuance of common stock - stock option and other plans, value	405	405
Issuance of common stock - stock option and other plans, shares		19
Issuance of common stock - restricted stock awards, net of cancelled awards, value	680	680
Issuance of common stock - restricted stock awards, net of cancelled awards, shares		197
Stock Repurchased During Period, Shares		(21)
Stock Repurchased and Retired During Period, Value	(522)	(522)
Dividends, Preferred Stock, Cash	(12)us-gaap_DividendsPreferredStockCash
Cash dividends paid on common stock	(6,154)us-gaap_DividendsCommonStockCash		(6,154)
Balance, value at Mar. 31, 2014	1,074,491us-gaap_StockholdersEquity	861,125	216,192	(5,043)	2,217
Balance, shares at Mar. 31, 2014		52,600			9
Balance, value at Dec. 31, 2014	1,228,175us-gaap_StockholdersEquity	985,839	234,498	5,621	2,217
Balance, shares at Dec. 31, 2014		57,437			9
Net Income	24,361us-gaap_NetIncomeLoss		24,361
Other comprehensive income	8,665			8,665
Issuance of common stock - stock option and other plans, value	428	428
Issuance of common stock - stock option and other plans, shares		17
Issuance of common stock - restricted stock awards, net of cancelled awards, value	862	862
Issuance of common stock - restricted stock awards, net of cancelled awards, shares		273
Stock Repurchased During Period, Shares		(28)
Stock Repurchased and Retired During Period, Value	(781)	(781)
Dividends, Preferred Stock, Cash	(31)us-gaap_DividendsPreferredStockCash
Cash dividends paid on common stock	(17,236)us-gaap_DividendsCommonStockCash		(17,236)
Balance, value at Mar. 31, 2015	$ 1,244,443us-gaap_StockholdersEquity	$ 986,348	$ 241,592	$ 14,286	$ 2,217
Balance, shares at Mar. 31, 2015		57,699			9

Stock Issued During Period, Shares, Cashless Conversion of Warrants

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Stock Issued During Period, Value, Cashless Conversion of Warrants

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited.

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Number of share options (or share units) exercised during the current period.

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Value of stock related to Restricted Stock Awards issued during the period, net of the stock value of such awards forfeited.

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Value of stock issued as a result of the exercise of stock options.

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Number of shares that have been repurchased and retired during the period.

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Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

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