Agreement and Plan of Merger with Central Parking Corporation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended
	Mar. 31, 2012 member	Feb. 28, 2012 member
Agreement and Plan of Merger
Number of members in the board of directors	8	5
Minimum
Agreement and Plan of Merger
Issuance of Stock Consideration as a percentage of total number of shares of common stock outstanding before the issuance for which prior approval of stockholders required		20.00%
Senior secured credit facilities commitments
Commitment Letter
Maximum borrowing capacity		450,000
Revolving credit facility
Commitment Letter
Maximum borrowing capacity		200,000
Term of debt (in years)		5 years
Term loan facility
Commitment Letter
Maximum borrowing capacity		250,000
Central
Agreement and Plan of Merger
Shares of common stock to be issued to Central Stockholders		6,161,334
Cash consideration to be paid on the third anniversary of the closing of the Merger		27,000
Anniversary period from the closing of the merger for payment of cash consideration (in years)		3 years
Termination fee payable by the company to Central in one case		7,500
Commitment Letter
Assumption of debt, net of cash acquired		210,000
Central | Maximum
Agreement and Plan of Merger
Fees and expenses of other party payable upon termination of the Merger Agreement under specified circumstances		6,000