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								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Numerator [Abstract]
Net income attributable to CAI common stockholders used in the calculation of basic and diluted earnings per share	$ 15,591	$ 15,337	$ 16,931	$ 16,067	$ 17,411	$ 16,528	$ 15,135	$ 14,391	$ 63,926	$ 63,465	$ 50,189
Denominator [Abstract]
Weighted average shares used in the calculation of basic earnings per share (in shares)									22,157	19,495	19,295
Effect of dilutive securities (in shares)									515	450	398
Weighted average shares used in the calculation of diluted earnings per share (in shares)									22,672	19,945	19,693
Net income per share attributable to CAI common stockholders [Abstract]
Basic (in dollars per share)	$ 0.70	$ 0.69	$ 0.76	$ 0.73	$ 0.87	$ 0.86	$ 0.78	$ 0.75	$ 2.89	$ 3.26	$ 2.60
Diluted (in dollars per share)	$ 0.69	$ 0.68	$ 0.75	$ 0.71	$ 0.85	$ 0.84	$ 0.77	$ 0.73	$ 2.82	$ 3.18	$ 2.55