Assets Held For Sale (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Long Lived Assets Held-for-sale [Line Items]
Period Assets are Expected To Be Sold	12 months
Gain on disposal of assets held for sale	$ 11,786	$ 7,096
Equipment [Member]
Long Lived Assets Held-for-sale [Line Items]
Assets Held for Sale	32,300		$ 40,000
Gain on disposal of assets held for sale	11,800	7,100
Impairments	$ 0	$ 0