Supplemental Cash Flow Information (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Supplemental Cash Flow Information [Abstract]
Interest paid	$ 2,092	$ 539
Income taxes paid, net of refunds	151	1,594
Reclassification of available-for-sale securities to equity method investment	27,647	0
Securities received in exchange for financial instrument obligations	19,341	0
Contribution of advances by non-controlling interest	268	0
Restricted stock awards surrendered to satisfy tax withholding obligations upon vesting	$ 14	$ 0