Consolidated Statement of Changes in Equity (Parenthetical) (USD $)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Distributions to Partners, per Common Unit	$ 0.68	$ 0.68	$ 0.76

Aggregate distributions paid during the period for each common unit outstanding.

No definition available.

Name:	drlp_CommonUnitDistributionsPerUnitCashPaid
Namespace Prefix:	drlp_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration