Divestiture-Related Activities (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Divestiture-Related Activities [Abstract]
Gains on divestitures, net	$ 546	$ 1,276
Impairment losses	(2,424)	(794)
(Losses) gains on divestitures and impairment charges, net	$ (1,878)	$ 482

Amount, before tax, of (gain) loss recognized for the (reversal of write-down) write-down to fair value, less cost to sell, of a disposal group. Excludes discontinued operations.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration