Discontinued Operations - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2007 Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of earn-out agreements				2
Cumulative cash receipts received under ECU earn-out				$ 150,000,000
Payments received under 5CP earn-out	11,369,000	12,284,000	8,794,000
Total payments received under the 5CP earn-out	66,360,000
Excess cash received under 5CP earn-out	33,259,000
Cash transaction bonus payable	1,137,000	1,228,000	882,000
Net cash transaction bonus payable	3,768,000
Pretax earnings (loss) from results	(8,017,000)	(3,669,000)	2,103,000
Pretax gains from discontinued operations related to insurance settlements		$ 7,575,000	$ 6,000,000