Noncontrolling Interest (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($) item	Jun. 30, 2014 USD ($)
Redeemable Noncontrolling Interest
Number of firms in which entity holds majority ownership interest | item	4
Fair value of noncontrolling owners equity interests	$ 39,978
Redeemable noncontrolling interest
Balance, beginning of period	39,978
Net income	1,033	$ 1,209
Balance, end of period	$ 37,755
Redeemable Noncontrolling Interest
Redeemable Noncontrolling Interest
Number of firms in which entity holds majority ownership interest | item	4
Fair value of noncontrolling owners equity interests	$ 39,978	39,768
Redeemable noncontrolling interest
Balance, beginning of period	39,978	39,768
Net income	1,033	1,209
Distributions to redeemable noncontrolling interest	(1,895)	(1,854)
Additions and redemptions, net	(2,796)	(75)
Adjustments to fair value	1,435	7,501
Balance, end of period	$ 37,755	$ 46,549