Consolidation Of Variable Interest Entities (Narrative) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) item	Jun. 30, 2018 USD ($) item	Jun. 30, 2019 USD ($) item	Jun. 30, 2018 USD ($) item	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Variable Interest Entity [Line Items]
Net book value	$ 1,882,452,000		$ 1,882,452,000		$ 1,816,794,000
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Net book value	113,995,000		113,995,000		71,958,000
Cash	35,105,000	$ 24,348,000	35,105,000	$ 24,348,000	$ 25,211,000	$ 20,685,000
Collateralized Financing Obligations [Member]
Variable Interest Entity [Line Items]
Long-term debt	115,400,000		115,400,000
Term Loan [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Long-term debt	$ 39,000,000		$ 39,000,000
Containers [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Number of types of container fund arrangements | item			2
Number of container portfolios sold | item	0	0	0	0
Net book value	$ 123,900,000		$ 123,900,000
Cash	35,100,000		35,100,000
Gain (loss) recognized on initial consolidation of VIEs			0
Book value of containers sold	$ 65,000,000	$ 7,300,000	$ 65,000,000	$ 15,200,000