Long-Term Incentive Plan Units (Narrative) (Details) (USD $)	3 Months Ended		67 Months Ended		4 Months Ended	67 Months Ended		3 Months Ended		67 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2013 Independent Directors [Member] Long-Term Incentive Plan Units [Member]	Dec. 31, 2007 Manager [Member] Long-Term Incentive Plan Units [Member]	Mar. 31, 2013 Manager [Member] Long-Term Incentive Plan Units [Member]	Mar. 31, 2013 Dedicated Personnel [Member] Long-Term Incentive Plan Units [Member]	Mar. 31, 2013 Non-Manager [Member] Long-Term Incentive Plan Units [Member]	Mar. 31, 2012 Non-Manager [Member] Long-Term Incentive Plan Units [Member]	Mar. 31, 2013 Non-Manager [Member] Long-Term Incentive Plan Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
LTIP units granted				24,096	375,000		8,000
Aggregate expense associated with Manager LTIP, Since inception						$ 8,600,000
Vesting period								1 year
Allocated Share-based Compensation Expense	42,000	28,000						40,000	30,000	600,000
Common shares issued in connection with conversion since inception			10,000
Amount transferred from share-based LTIP awards to Shareholders Equity			$ 200,000