Sales of Assets (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
	May 17, 2019	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of real estate assets			$ 4,597
Pretax gain on sale of real estate		$ 25,908	$ 25,908
Assets held for sale				$ 1,089
Dallas, Texas [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale of real estate assets, amount	$ 28,000
Proceeds from sale of real estate assets	4,597
Real estate assets selling costs	1,000
Note receivable	$ 22,400
Notes receivable term	2 years
Additional contingency payment receivable if certain conditions are met	$ 1,000
Interest rate on promissory note during first year			3.50%
Interest rate on promissory note during second year			4.50%