Bradley Agreement (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended	1 Months Ended	3 Months Ended
	Mar. 31, 2013 Deficiency payments	Dec. 31, 2012 Deficiency payments	Apr. 30, 2000 Bradley International Airport parking facilities operating agreement	Mar. 31, 2013 Bradley International Airport parking facilities operating agreement item	Mar. 31, 2012 Bradley International Airport parking facilities operating agreement	Mar. 31, 2013 Bradley International Airport parking facilities operating agreement Low end of the range	Mar. 31, 2013 Bradley International Airport parking facilities operating agreement High end of the range	Apr. 06, 2000 Bradley International Airport parking facilities operating agreement State of Connecticut special facility revenue bonds	Mar. 31, 2013 Bradley International Airport parking facilities operating agreement State of Connecticut special facility revenue bonds Low end of the range	Mar. 31, 2013 Bradley International Airport parking facilities operating agreement State of Connecticut special facility revenue bonds High end of the range	Apr. 06, 2000 Bradley International Airport parking facilities operating agreement Non-taxable series A bonds	Apr. 06, 2000 Bradley International Airport parking facilities operating agreement Taxable series B bonds
Agreement
Agreement period with the State of Connecticut for operation of parking spaces			25 years
Number of garage parking spaces at Bradley International Airport operated				3,500
Revenue bonds issued								$ 53,800			$ 47,700	$ 6,100
Annual principal and interest on revenue bonds									3,600	4,500
Annual minimum guaranteed payment to the State by the trustee				2,621	2,567	8,300	13,200
Deficiency payments:
Balance at the beginning of the year	14,598	13,407
Deficiency payments made	403	1,658
Deficiency payments received		(467)
Balance at the end of the period	15,001	14,598
Maximum premium percentage on initial deficiency payment				10.00%
Period after notification to deliver deficiency amount to trustee				3 days
Deficiency payments (net of repayments received)				403	779
Compensation
Number of operating profit tiers				3
Management fee apportioned to the entity (as a percent)				60.00%
Management fee apportioned to an un-affiliated entity (as a percent)				40.00%
Unrecognized cumulative management fees				9
Management fees				$ 0	$ 0