Secured Debt (Tables)

12 Months Ended

Dec. 31, 2011

Secured Debt [Abstract]

Secured debt instruments

					For the Year Ended December 31, 2011
	Principal Outstanding				Weighted			Weighted		Number of
	December 31,				Average			Average		Communities
	2011		2010		Interest Rate			Years to Maturity		Encumbered
Fixed Rate Debt
Mortgage notes payable	$	590,208	$	292,236		5.10	%		4.7		10
Tax-exempt secured notes payable		—		13,325	NA				—		—
Fannie Mae credit facilities		744,509		897,318		5.14	%		6.0		12
Total fixed rate secured debt		1,334,717		1,202,879		5.12	%		5.4		22
Variable Rate Debt
Mortgage notes payable		151,685		405,641		2.08	%		1.4		6
Tax-exempt secured notes payable		94,700		94,700		0.77	%		10.6		2
Fannie Mae credit facilities		310,451		260,450		1.63	%		4.6		28
Total variable rate secured debt		556,836		760,791		1.60	%		4.8		36
Total secured debt	$	1,891,553	$	1,963,670		4.10	%		5.2		58

Secured credit facilities

	December 31,
	2011			2010
	(dollar amounts in thousands)
Borrowings outstanding	$	1,054,960		$	1,157,768
Weighted average borrowings during the period ended		1,139,588			1,198,771
Maximum daily borrowings during the period ended		1,157,557			1,209,739
Weighted average interest rate during the period ended		4.4	%		4.6	%
Weighted average interest rate at the end of the period		4.1	%		4.5	%

Aggregate maturities of secured debt

	Fixed				Variable
	Mortgage		Credit		Mortgage		Tax-Exempt		Credit		Total
Year	Notes		Facilities		Notes		Notes Payable		Facilities		Secured
2012	$	65,480	$	77,944	$	64,345	$	—	$	99,042	$	306,811
2013		23,378		38,632		62,490		—		—		124,500
2014		81,101		3,328		24,850		—		—		109,279
2015		201,691		3,522		—		—		—		205,213
2016		140,180		3,702		—		—		—		143,882
Thereafter		78,378		617,381		—		94,700		211,409		1,001,868
Total	$	590,208	$	744,509	$	151,685	$	94,700	$	310,451	$	1,891,553