Equity (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 quarters
Common units - issued in connection with the DRIP	238,314
Relinquishment of rights of incentive distributions	$ 220
Number of periods of incentive distributions to be relinquished in future periods contingent upon closing of proposed transaction.	16
Credit Suisse [Member]
Proceeds from issuance of common units under equity distribution agreement, net of commission	76.7
Common units - outstanding, value	0
Distribution Reinvestment Plan [Member]
Units authorized under the DRIP	5,750,000
Net proceeds from issuance of common units under the DRIP	$ 10.6
DRIP Capacity	5,158,007