Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012 Y	Dec. 31, 2011	Dec. 31, 2010	Jul. 28, 2011
Goodwill And Other Intangible Assets [Line Items]
Business acquisition, cash paid				$ 10,600,000
Fair value of contingent consideration				900,000
Contingent consideration expiration year	2015
Period for performance evaluation, years	4
Business acquisition, effective date	Jul. 28, 2011
Amortization of intangible assets, years	5 years
Acquisition related costs		700,000
Amortization of other intangible assets	2,424,000	1,713,000	822,000
Other Noncurrent Liabilities
Goodwill And Other Intangible Assets [Line Items]
Fair value of contingent consideration	600,000	1,000,000
Maximum
Goodwill And Other Intangible Assets [Line Items]
Potential cash payment to shareholders	$ 12,000,000