Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Line Items]
Release of Valuation Allowance		$ 174,500,000
Valuation Allowance	1,600,000	3,300,000
Reduction of recorded value of the Company's state net deferred tax asset	3,400,000
Deferred tax assets related to net operating losses for federal income tax purposes	49,001,000	63,886,000
Deferred tax assets related to net capital losses for federal income tax purposes	1,122,000	1,760,000
Future tax return benefits	14,200,000
Deferred tax assets previously reported	108,713,000	136,829,000	93,000,000
Deferred tax assets relating to net operating losses and intangible assets			89,000,000
Internal Revenue			4,000,000
Gross deferred tax assets and related offsetting valuation allowance		31,800,000
Unrecognized tax benefit related to uncertain tax position	31,800,000
Unrecognized tax benefits	31,800,000
Unrecognized tax benefits, maturity period	12 months
Domestic Tax Authority [Member]
Income Taxes [Line Items]
Deferred tax assets related to net operating losses for federal income tax purposes	39,700,000
Deferred tax assets related to net capital losses for federal income tax purposes	300,000
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Deferred tax assets related to net operating losses for federal income tax purposes	9,300,000
Deferred tax assets related to net capital losses for federal income tax purposes	$ 800,000