Related Party Transactions (Narrative) (Details)	12 Months Ended
	Dec. 31, 2012
Related Party Transaction [Line Items]
Incentive management fees as a percentage of cash distributions from operations	4.00%
Operating Leases [Member]
Related Party Transaction [Line Items]
Equipment management fees as a percentage of gross revenue	3.50%
Full Payout Leases [Member]
Related Party Transaction [Line Items]
Equipment management fees as a percentage of gross revenue	2.00%