CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
CONSOLIDATED STATEMENTS OF INCOME
Rental income from a lessee that qualifies as a related party	$ 1,122	$ 1,095	$ 3,357	$ 3,275
Straight-line rental income from a lessee that qualifies as a related party	3	31	19	101
Interest income from an entity that qualifies as a related party		$ 0		$ 235