Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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Amount of the cost of borrowed funds accounted for as interest expense.

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The loss recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

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Interest Rate Swaps (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Interest Rate Swaps (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Apr. 05, 2017
Derivative [Line Items]
Interest expense related to payments on interest rate swaps	$ 6,386	$ 7,958	$ 22,699	$ 22,474
Increase (decrease) in fair value of interest rate swaps	1,429	(286)	9,974	(1,785)
Other Assets.
Derivative [Line Items]
Derivative, Fair Value, Net	11,400		11,400
Interest Rate Swap
Derivative [Line Items]
Derivative instruments, notional amount						$ 400,000
Ineffectiveness recognized	0		0
Increase (decrease) in fair value of interest rate swaps		$ 0		$ 0
Interest Rate Swap \| Term Loan Maturing April 27, 2022
Derivative [Line Items]
Derivative instruments, notional amount						200,000
Interest Rate Swap \| Term Loan Maturing December 17,2021
Derivative [Line Items]
Derivative instruments, notional amount						$ 200,000
Cash flow hedging \| Interest Rate Swap
Derivative [Line Items]
Derivative instruments, notional amount	400,000		400,000		$ 400,000
Derivative, Fair Value, Net	$ 11,422		$ 11,422		$ 1,449