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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Amount after tax 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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Interest Rate Swaps (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Interest Rate Swaps (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Apr. 05, 2017
Derivative [Line Items]
Interest expense related to payments on interest rate swaps	$ 8,203	$ 7,647	$ 16,313	$ 14,516
Increase (decrease) in fair value of interest rate swaps	2,563	(1,499)	8,545	(1,499)
Other Assets.
Derivative [Line Items]
Derivative, Fair Value, Net	10,000		10,000
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	$ 9,994		$ 9,994		$ 1,449