Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 18,611	$ 9,460
Other comprehensive income, net of tax
Net change in fair value of securities available for sale	4,081	1,561
Net change in fair value of cash flow hedges	123	82
Net change in other comprehensive income for defined benefit postretirement plans	60	76
Total other comprehensive income	4,264	1,719
Total comprehensive income	$ 22,875	$ 11,179

Net of tax amount of the appreciation (loss) in the value of unsold available-for-sale securities.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Other Comprehensive Income
-URI http://asc.fasb.org/extlink&oid=51831270

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

+ References

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-Publisher FASB
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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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

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Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

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