Loans Receivable - Activity Related to Loans Receivable (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Receivables [Abstract]
Balance at beginning of year	$ 211,250,000	$ 114,333,000
Purchase and advances	22,314,000	175,550,000
Interest (received) accrued, net	(514,000)	516,000
Repayments / sale proceeds	(75,407,000)	(68,824,000)	(70,289,000)
Elimination of 1515 Market Street in consolidation	(60,279,000)
Loan accretion	4,121,000	8,333,000	13,401,000
Discount accretion received in cash	(37,000)	(15,720,000)	(13,290,000)
Provision for loss on loans receivable	(348,000)	0	0
Conversion of 180 North Michigan loan to equity investments		(2,938,000)	(4,650,000)
Balance at end of year	$ 101,100,000	$ 211,250,000	$ 114,333,000