Earnings Per Share (Reconciliation Of Basic And Diluted Net Income Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Numerator [Abstract]
Net income attributable to CAI common stockholders used in the calculation of basic and diluted earnings per share	$ 16,395	$ 15,337	$ 44,112	$ 48,335
Denominator [Abstract]
Weighted average shares used in the calculation of basic earnings per share (in shares)	20,936	22,186	21,193	22,139
Effect of dilutive securities, Stock options and restricted stock (in shares)	393	459	429	535
Weighted average shares used in the calculation of diluted earnings per share (in shares)	21,329	22,645	21,622	22,674
Net income per share attributable to CAI common stockholders [Abstract]
Basic (in dollars per share)	$ 0.78	$ 0.69	$ 2.08	$ 2.18
Diluted (in dollars per share)	$ 0.77	$ 0.68	$ 2.04	$ 2.13