Supplemental Cash Flow Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Supplemental disclosures of cash flows: [Abstract]
Interest paid	$ 273	$ 68
Income taxes paid	1,582	0
Non-cash investing and financing activities:
Net unrealized gain on marketable securities, net of taxes	642	382
Issuance of common stock for acquisition of Sun Well	$ 0	$ 60,825