Basis of Presentation (Details Textual) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax	$ (313)	$ 740
Other Tax Expense (Benefit)	$ (110)	259
Percentage Of Credit Losses On Available For Sale Debt Securities To Total Investment Portfolio	90.00%
Additional excess tax benefits	$ 2,518	10,164
Payments Related to Tax Withholding for Share-based Compensation	2,532	$ 3,231
Federal income taxes [Member]
Additional excess tax benefits	$ (2,450)

Disclosure of accounting policy pertaining to pending accounting standards.

No definition available.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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Amount before tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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