Debt (Bank Of America Line Of Credit) (Narrative) (Details) - USD ($) $ in Thousands			1 Months Ended	9 Months Ended	12 Months Ended
	Nov. 05, 2019	Aug. 08, 2019	Oct. 31, 2016	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Contractual facility				$ 279,215	$ 252,929
US Bank Of America Line Of Credit [Member]
Debt Instrument [Line Items]
Maturity date		Sep. 01, 2020	Oct. 31, 2019	Oct. 01, 2020	Oct. 31, 2019
Contractual facility			$ 5,000	$ 5,000	$ 5,000
Extension period		10 months
Subsequent Event [Member] | US Bank Of America Line Of Credit [Member]
Debt Instrument [Line Items]
Extension period	1 month