Noncontrolling Interest (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 item	Dec. 31, 2012	Dec. 31, 2011
Redeemable Noncontrolling Interest
Number of real estate investment trust subsidiaries	2
Number of firms in which entity holds majority ownership interest	5
Fair value of noncontrolling owners equity interests	$ 39,768	$ 41,112
Redeemable noncontrolling interest
Balance, beginning of period	41,112
Net income	2,507	1,084	1,956
Distributions to redeemable noncontrolling interest			(1,678)
Balance, end of period	39,768	41,112
Redeemable Noncontrolling Interest
Redeemable Noncontrolling Interest
Fair value of noncontrolling owners equity interests	39,768	41,112	44,643
Redeemable noncontrolling interest
Balance, beginning of period	41,112	44,643	45,676
Net income	2,507	1,084	1,956
Distributions to redeemable noncontrolling interest	(1,150)	(1,451)	(2,061)
Additions and redemptions, net	(1,922)	(2,811)	(5,304)
Adjustments to fair value	(779)	(353)	5,003
Other			(627)
Balance, end of period	$ 39,768	$ 41,112	$ 44,643