Debt (Schedule Of Debt) (Details) - USD ($) $ in Thousands		9 Months Ended
	Apr. 19, 2018	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 199,621	$ 135,869
Gross Debt, Long-term Outstanding		1,791,273	1,578,666
Debt issuance costs, Current Outstanding		(5,058)	(3,820)
Debt issuance costs, Long-term Outstanding		(13,853)	(7,893)
Total Debt, Current Outstanding		194,563	132,049
Total Debt, Long-term Outstanding		1,777,420	1,570,773
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Gross Debt, Long-term Outstanding		$ 146,000	$ 528,000
Average Interest		3.90%	3.20%
Maturity		Jun. 01, 2023
Revolving Credit Facility [Member] | CAI Rail [Member]
Debt Instrument [Line Items]
Gross Debt, Long-term Outstanding		$ 306,000	$ 272,000
Average Interest		3.70%	3.20%
Maturity		Oct. 01, 2020
Revolving Credit Facility [Member] | CAI International GmbH [Member]
Debt Instrument [Line Items]
Gross Debt, Long-term Outstanding		$ 19,733	$ 14,736
Average Interest		2.00%	2.00%
Maturity		Sep. 01, 2020
Term Loan [Member]
Debt Instrument [Line Items]
Maturity	Apr. 30, 2023
Term Loan [Member] | CAI Rail [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 1,230	$ 1,198
Gross Debt, Long-term Outstanding		$ 15,598	$ 16,524
Average Interest		3.40%	3.40%
Maturity		Dec. 01, 2020
Term Loan [Member] | Development Bank of Japan [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 1,800	$ 21,900
Gross Debt, Long-term Outstanding		$ 27,750
Average Interest		4.30%	3.40%
Maturity		Apr. 01, 2023
Term Loan [Member] | Consortium of Banks, Note Dated October 1, 2014 [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 6,750	$ 9,000
Gross Debt, Long-term Outstanding		$ 107,250	$ 111,750
Average Interest		3.80%	3.10%
Maturity		Oct. 01, 2019
Term Loan [Member] | Consortium of Banks, Note Dated April 11, 2012 [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 7,000	$ 7,000
Gross Debt, Long-term Outstanding		$ 77,250	$ 82,500
Average Interest		4.00%	3.30%
Maturity		Jun. 01, 2021
Term Loan [Member] | Consortium Of Banks Note Dated August 30 2016 [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 2,882	$ 2,805
Gross Debt, Long-term Outstanding		$ 41,388	$ 43,560
Average Interest		3.60%	3.60%
Maturity		Aug. 01, 2021
Senior Secured Notes [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 6,110	$ 6,110
Gross Debt, Long-term Outstanding		$ 52,775	$ 58,885
Average Interest		4.90%	4.90%
Maturity		Sep. 01, 2022
Collateralized Financing Obligations [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 37,388	$ 22,549
Gross Debt, Long-term Outstanding		$ 65,717	$ 69,441
Average Interest		1.10%	1.20%
Maturity		Sep. 01, 2021
Variable Interest Entity, Primary Beneficiary [Member]
Debt Instrument [Line Items]
Total Debt, Current Outstanding		$ 39,302	$ 22,549
Total Debt, Long-term Outstanding		65,717	72,727
Variable Interest Entity, Primary Beneficiary [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 1,914
Gross Debt, Long-term Outstanding			$ 3,286
Average Interest		3.00%	2.70%
Maturity		Jun. 01, 2019
Series 2012-1 Asset-Backed Notes [Member] | Asset Backed Notes [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 17,100	$ 17,100
Gross Debt, Long-term Outstanding		$ 52,725	$ 65,550
Average Interest		3.50%	3.50%
Maturity		Oct. 01, 2027
Series 2013-1 Asset-Backed Notes [Member] | Asset Backed Notes [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 22,900	$ 22,900
Gross Debt, Long-term Outstanding		$ 80,150	$ 97,325
Average Interest		3.40%	3.40%
Maturity		Mar. 01, 2028
Series 2017-1 Asset-Backed Notes [Member] | Asset Backed Notes [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 25,307	$ 25,307
Gross Debt, Long-term Outstanding		$ 196,129	$ 215,109
Average Interest		3.70%	3.70%
Maturity		Jun. 01, 2042
Series 2018-1 Asset-Backed Notes [Member] | Asset Backed Notes [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 34,890
Gross Debt, Long-term Outstanding		$ 293,658
Average Interest		4.00%
Maturity		Feb. 01, 2043
Series 2018-2 Asset-Backed Notes [Member] | Asset Backed Notes [Member]
Debt Instrument [Line Items]
Gross Debt, Current Outstanding		$ 34,350
Gross Debt, Long-term Outstanding		$ 309,150
Average Interest		4.40%
Maturity		Sep. 01, 2043