Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 segment	Dec. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments	1
Number of reportable segments	1
Percentage of operating revenues	100.00%	100.00%
Period subject to income tax examination		generally subject to examination by U.S. federal (or state and local) income tax authorities for three years from the filing of a tax return.
Provision for franchise fees and state taxes	$ 40,000	$ 2,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Required assets value of financial institutions for cash deposits	10,000,000,000
Operating leases, initial terms	24 months
Operating leases, period for non accrual status	90 days
Direct financing leases, period for non accrual status	90 days
Drydocking equipment period	24 months
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
U.S. Treaasury instruments maturity period	90 days
Cash deposits, insured amount	$ 250,000
Operating leases, initial terms	120 months
Drydocking equipment period	30 months