Commitments And Contingencies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) item	Dec. 31, 2016 USD ($) item	Dec. 31, 2015 USD ($)
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Lease term	5 years
Office facility expense	$ 2,000	$ 1,700	$ 1,500
Number of outstanding letters of credit | item	1	1
Outstanding letter of credit	$ 100	$ 100
Rental equipment payable	92,415	$ 25,207
Future minimum lease payments under operating lease agreements	5,450
Containers [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Commitments to purchase rental equipment	17,600
Railcars [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Commitments to purchase rental equipment	$ 88,700