Interest and Other Investment Income (Loss), Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Dividends and interest on marketable securities	$ 3,200	$ 2,804	$ 9,504	$ 8,344
Mark-to-market of investments in our deferred compensation plan	1,352	269	8,132	6,207
Interest on mezzanine loans receivable	404	4,766	3,524	14,783
Loss from the mark-to-market of J.C. Penney derivative position	0	(20,012)	0	(33,487)
Non-cash impairment loss on J.C. Penney common shares	0	0	0	(39,487)
Income from prepayment penalties in connection with the repayment of a mezzanine loan	0	0	0	5,267
Other, net	2,646	1,898	7,770	5,438
Interest and other investment (loss) income, net	$ 7,602	$ (10,275)	$ 28,930	$ (32,935)