Derivative Financial Instruments - Impact of Derivatives on Consolidated Statements of Income (Details) - Interest rate swaps - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Trading
Total	$ (8,623)	$ (3,397)	$ (6,806)	$ (7,567)
Designated as Hedging Instrument \| Fair Value Hedges
Fair Value Hedges
Hedge ineffectiveness realized gains (losses) recorded in earnings	(2,914)	(3,711)	2,939	(7,878)
Realized gains (losses) recorded in interest expense	(2,812)	2,881	(3,326)	7,428
Trading
Total	(5,726)	(830)	(387)	(450)
Designated as Hedging Instrument \| Cash Flow Hedges
Cash Flow Hedges
Hedge ineffectiveness gains (losses) recorded in earnings	65	(75)	2,749	(147)
Realized losses recorded in interest expense	(543)	(2,669)	(2,104)	(6,008)
Trading
Total	(478)	(2,744)	645	(6,155)
Trading
Trading
Interest reclassification	(239)	(101)	(129)	(20)
Realized losses recorded in earnings	(2,180)	278	(6,935)	(942)
Total	$ (2,419)	$ 177	$ (7,064)	$ (962)

Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Hedge Ineffectiveness

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Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Interest Reclassification

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
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The net gain (loss) relating to components of the gain (loss) on the cash flow hedging instrument excluded from the assessment of cash flow hedge effectiveness. Recognized in earnings.

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Net gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. Recognized in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

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Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge.

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