Derivative and Hedging Activities (Details) $ in Thousands		3 Months Ended		9 Months Ended
	Jun. 06, 2019 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Cash Paid on Hedge	$ (20,400)			$ (20,430)	$ 0
Unrealized Gain (Loss) on Derivatives		$ 0	$ 5,200	(13,000)	$ 14,000
Derivative, Notional Amount	$ 300,000
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net		1,300		1,300
Interest Rate Derivative Liabilities, at Fair Value		0		0			$ 7,400
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		(300)		500
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Derivative Assets, at Fair Value		0		0			0
Interest Rate Derivative Liabilities, at Fair Value		$ 0		$ 0			$ 7,400
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Number of Interest Rate Derivatives Held			5		5
Derivative, Notional Amount			$ 400,000		$ 400,000	$ 300,000