Quarterly Results of Operations (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Quarterly Results of Operations (Unaudited) [Abstract]

Summary of quarterly results of operations

The following is a summary of quarterly results of operations for 2011 and 2010 ($ in thousands, except per share and dividend amounts):

	Quarter ended		Quarter ended		Quarter ended		Quarter ended
	December 31		September 30		June 30		March 31
2011:
Total property revenues	$	123,151	$	118,002	$	115,657	$	111,968
Income before discontinued operations	$	14,713	$	11,992	$	10,720	$	12,357
Net income	$	17,867	$	11,085	$	16,053	$	12,511
Net income available to common stockholders	$	13,937	$	7,688	$	10,325	$	8,418
Per share data:
Net income:
Basic	$	0.42	$	0.23	$	0.32	$	0.27
Diluted	$	0.42	$	0.23	$	0.32	$	0.27
Market price:
High	$	148.44	$	145.40	$	138.31	$	124.41
Low	$	111.25	$	119.15	$	122.67	$	109.98
Close	$	140.51	$	120.04	$	135.29	$	124.00
Dividends declared	$	1.04	$	1.04	$	1.04	$	1.04
2010:
Total property revenues	$	107,465	$	103,225	$	98,959	$	99,085
Income before discontinued operations	$	8,494	$	10,260	$	13,643	$	17,680
Net income	$	8,628	$	10,426	$	13,869	$	17,859
Net income available to common stockholders	$	4,778	$	6,377	$	9,482	$	13,127
Per share data:
Net income:
Basic	$	0.16	$	0.21	$	0.32	$	0.45
Diluted	$	0.16	$	0.21	$	0.32	$	0.45
Market price:
High	$	117.12	$	115.08	$	113.03	$	93.98
Low	$	105.60	$	92.62	$	89.23	$	76.35
Close	$	114.22	$	109.44	$	97.54	$	89.95
Dividends declared	$	1.03	$	1.03	$	1.03	$	1.03