Debt And Capital Lease Obligations (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Percentage of aggregate principal to prepay, minimum (in hundredths)	10.00%
Revolving Credit Facility [Abstract]
Number of business days short term borrowings payable, Maximum	10 days
Term Loans [Abstract]
Proceeds used to repay credit facility	$ 124,400,000
Terms	The Base Rate is defined as the highest of (i) the federal funds rate plus 1/2 of 1.0%, (ii) the prime rate (as published in The Wall Street Journal), and (iii) the Eurodollar rate (for three-month loans) plus 1.0%.
Long term debt maturity [Abstract]
Long-term debt	1,086,432,000	1,058,628,000
Restricted cash	8,998,000	9,253,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum credit commitment	760,000,000
Maximum amount credit facility might be increased	960,000,000
Average Interest (in hundredths)	1.90%	1.90%
Revolving Credit Facility [Abstract]
Availability borrowing capacity	488,400,000
Revolving Credit Facility [Member] | CAI Rail Inc [Member]
Debt Instrument [Line Items]
Maximum credit commitment	85,000,000
Average Interest (in hundredths)	2.40%	2.40%
Revolving Credit Facility [Abstract]
Availability borrowing capacity	28,000,000
Term Loan [Member]
Term Loans [Abstract]
Amount outstanding under the facility	117,500,000
Term Loan [Member] | Development Bank of Japan [Member]
Debt Instrument [Line Items]
Principal amount of loan	10,000,000
Average Interest (in hundredths)	2.30%	2.30%
Term Loans [Abstract]
Term of loan	5 years
Number of quarterly installments	19
Quarterly payments of principal	200,000
Debt instrument final payment	6,200,000
Amount outstanding under the facility	35,100,000
Term Loan [Member] | Consortium of Banks [Member]
Debt Instrument [Line Items]
Maximum credit commitment	300,000,000
Average Interest (in hundredths)	2.50%	2.50%
Term Loans [Abstract]
Quarterly payments of principal	1,900,000
Amount outstanding under the facility	249,400,000
Periodic payment of principal balance	125,000,000
Amortization term of facility	6 years
Basis spread on variable rate (in hundredths)	0.50%
Term Loan [Member] | Consortium of Banks, Note Dated April 11, 2012 [Member]
Debt Instrument [Line Items]
Maximum credit commitment	142,000,000
Maximum amount credit facility might be increased	200,000,000
Average Interest (in hundredths)	2.20%	2.20%
Term Loans [Abstract]
Term of loan	5 years
Amount outstanding under the facility	126,800,000
Periodic payments specified as percentage of drawn amount (in hundredths)	1.75%
Term Loan [Member] | Eurodollar Rate [Member] | Consortium of Banks [Member]
Term Loans [Abstract]
Basis spread on variable rate (in hundredths)	1.00%
Senior Secured Notes [Member]
Debt Instrument [Line Items]
Average Interest (in hundredths)	4.90%	4.90%
Term Loans [Abstract]
Amount outstanding under the facility	90,600,000
Long term debt maturity [Abstract]
Long-term debt	103,000,000
Asset Backed Warehouse Facility [Member]
Debt Instrument [Line Items]
Principal amount of loan	171,000,000
Fixed rate, asset-backed notes	3.47%
Term Loans [Abstract]
Proceeds used for working capital purposes	229,000,000
Amount outstanding under the facility	146,800,000
Asset-backed Securities [Member]
Debt Instrument [Line Items]
Principal amount of loan	229,000,000
Average Interest (in hundredths)	3.40%	3.40%
Fixed rate, asset-backed notes	3.35%
Term Loans [Abstract]
Amount outstanding under the facility	206,100,000
Long term debt maturity [Abstract]
Restricted cash	9,000,000
Collateralized Financing Obligation [Member]
Debt Instrument [Line Items]
Average Interest (in hundredths)	1.00%	1.00%
Long term debt maturity [Abstract]
Long-term debt	109,000,000
Capital Lease Obligations [Abstract]
Average fixed and floating interest rates	1.00%
Maturity date range start	Jun. 01, 2015
Maturity date range end	Mar. 01, 2017
Swing Line Loans [Member]
Debt Instrument [Line Items]
Maximum credit commitment	10,000,000
Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Maximum credit commitment	15,000,000
Letter of Credit [Member]
Revolving Credit Facility [Abstract]
Letters of credit outstanding	100,000
Term Loan II [Member]
Term Loans [Abstract]
Debt instrument final payment	21,500,000
Term Loan II [Member] | Development Bank of Japan [Member]
Debt Instrument [Line Items]
Principal amount of loan	30,000,000
Term Loans [Abstract]
Term of loan	5 years
Number of quarterly installments	19
Quarterly payments of principal	500,000
Capital Lease Obligations [Member]
Capital Lease Obligations [Abstract]
Average fixed and floating interest rates	2.30%
Maturity date range start	Jun. 01, 2014
Maturity date range end	Jun. 01, 2019
Estimated future principal and interest payments under capital lease obligations [Abstract]
Capital lease obligation	$ 4,800,000