Fair Value Measures And Other Financial Instruments (Narrative) (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended										1 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 Fixed Rate Debt [Member]	Dec. 31, 2011 Fixed Rate Debt [Member]	Jun. 30, 2012 Variable Rate Debt [Member]	Dec. 31, 2011 Variable Rate Debt [Member]	Jun. 30, 2012 Fair Value, Inputs, Level 3 [Member] Atlanta Condominium Project [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Atlanta Condominium Project [Member]	Jun. 30, 2012 Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2011 Three Interest Rate Swap [Member]	Jan. 31, 2012 Fourth Interest Rate Swap [Member]	Mar. 31, 2012 Term Loans Fully Drawn [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notional amounts										$ 230,000	$ 70,000
Derivative, fixed interest rate	3.44%									1.55%	1.50%	3.44%
LIBOR rate											one-month
Net liabilities								9,907	2,641
Accumulated comprehensive income (loss) to interest expense, future periods	3,738
Termination payment	9,929
Fair value of debt		801,724	885,455	227,834	137,495
Carrying value of debt		737,582	835,443	230,000	135,000
Fair value of contractual obligation						$ 3,731	$ 5,348