Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

Fair Value Measurements [Abstract]

Fair Value, Assets Measured on Recurring Basis

		As of December 31, 2016
(Amounts in thousands)		Total		Level 1		Level 2		Level 3
	Marketable securities	$	37,918	$	37,918	$	-	$	-
		As of December 31, 2015
(Amounts in thousands)		Total		Level 1		Level 2		Level 3
	Marketable securities	$	43,191	$	43,191	$	-	$	-

Fair Value, by Balance Sheet Grouping

			As of December 31, 2016				As of December 31, 2015
			Carrying		Fair		Carrying		Fair
(Amounts in thousands)			Amount		Value		Amount		Value
Assets:
	Cash equivalents	$	256,370	$	256,370	$	226,476	$	226,476
Liabilities:
	Mortgages payable (excluding deferred debt issuance costs, net)	$	1,056,147	$	1,045,000	$	1,059,587	$	1,054,000