Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Student Housing Operations:
Revenues from external customers	$ 35,285	$ 36,526	$ 67,329	$ 69,525
Operating expenses	32,150	32,538	60,345	61,654
Equity in earnings (losses) of unconsolidated entities	(891)	1,896	(572)	2,306
Operating income	2,244	5,884	6,412	10,177
Nonoperating expenses	(2,846)	(2,100)	(6,156)	(4,948)
Net income	(392)	3,940	656	6,107
Net income attributable to noncontrolling interest	12	19	(3)	30
Net income attributable to common stockholders	0	260	0	528
Capital expenditures			(802)	(1,194)
Investment in unconsolidated entities	370,538		370,538		324,838
Total consolidated revenues	10,622	14,368	18,058	25,795
Interest expense	(2,950)	(2,789)	(6,326)	(5,673)
Net income (loss) before income tax benefit	(602)	3,784	256	5,229
Total assets at end of period	1,272,636		1,272,636		1,182,679
Student Housing Operations [Member]
Student Housing Operations:
Revenues from external customers	24,663	22,158	49,271	43,730
Operating expenses	17,841	15,597	35,341	30,885
Income from wholly-owned student housing operations	6,822	6,561	13,930	12,845
Equity in earnings (losses) of unconsolidated entities	(891)	1,896	(572)	2,306
Operating income	5,931	8,457	13,358	15,151
Nonoperating expenses	(1,209)	(2,563)	(5,150)	(5,080)
Net income	4,722	5,894	8,208	10,071
Net income attributable to noncontrolling interest	46	42	80	80
Net income attributable to common stockholders	4,676	5,852	8,128	9,991
Depreciation and amortization	6,974	5,711	13,744	11,247
Capital expenditures	51,087	38,042	81,305	63,737
Investment in unconsolidated entities	370,538	191,435	370,538	191,435
Total segment assets at end of period	1,147,791	1,034,289	1,147,791	1,034,289
Development Construction and Management Services [Member]
Student Housing Operations:
Revenues from external customers	10,622	14,368	18,058	25,795
Operating expenses	45,395	45,310	76,815	74,796
Net income	2,537	2,549	5,387	3,683
Net income attributable to noncontrolling interest	25	24	52	35
Net income attributable to common stockholders	2,512	2,525	5,335	3,648
Depreciation and amortization	24	59	25	109
Intersegment revenues	37,310	33,491	64,144	52,684
Total revenues	47,932	47,859	82,202	78,479
Total segment assets at end of period	81,699	57,434	81,699	57,434
Reconciliations [Member]
Student Housing Operations:
Intersegment revenues	(37,310)	(33,491)	(64,144)	(52,684)
Total revenues	72,595	70,017	131,473	122,209
Total consolidated revenues	35,285	36,526	67,329	69,525
Segment operating income	8,468	11,006	18,745	18,834
Interest expense	(2,950)	(2,789)	(6,326)	(5,673)
Net unallocated expenses related to corporate overhead	(6,224)	(5,122)	(12,333)	(8,657)
Other income	104	689	170	725
Net income (loss) before income tax benefit	(602)	3,784	256	5,229
Total segment assets at end of period	1,229,490	1,091,723	1,229,490	1,091,723
Unallocated corporate assets and eliminations	43,146	22,165	43,146	22,165
Total assets at end of period	$ 1,272,636	$ 1,113,888	$ 1,272,636	$ 1,113,888