CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
CONSOLIDATED STATEMENTS OF INCOME
Rental income from a lessee that qualifies as a related party	$ 1,068	$ 1,042	$ 2,127	$ 2,076
Straight-line rental income from a lessee that qualifies as a related party	57	83	123	175
Interest income from an entity that qualifies as a related party	$ 180	$ 180	$ 360	$ 360