Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards expire in 2030			$ 4,800,000
Net operating loss carry forwards, Expiration date one			2030
Net operating loss carry forwards expire in 2031			8,800,000
Net operating loss carry forwards, Expiration date two			2031
Net operating loss carry forwards expire in 2032			10,300,000
Net operating loss carry forwards, Expiration date three			2032
Net operating loss carryforwards, Expiration date	2030
Deferred tax assets, Valuation allowance	30,800,000
Projected cumulative tax losses period	4 years
Period for net unrealized pre-acquisition built-in losses	5 years
Gross proceeds from the sale of common stock	113,900,000
Expiration period for net unrealized pre-acquisition built-in losses	Oct. 07, 2015
Future utilization of built-in losses	53,000,000
Limited future utilization of built-in losses	1,100,000
Income tax provision	813,000	517,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Federal net operating loss carryforwards			23,900,000
Federal taxable net operating losses	2,800,000
State Income Tax [Member]
Operating Loss Carryforwards [Line Items]
Income tax provision	99,000
Federal Alternative Minimum Tax [Member]
Operating Loss Carryforwards [Line Items]
Income tax provision	56,000
Net Deferred Tax Asset [Member]
Operating Loss Carryforwards [Line Items]
Income tax provision	658,000
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Estimated unrealized built-in losses	8,000,000
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Estimated unrealized built-in losses	$ 9,000,000