Fair Value Measurements - Additional Information (Detail) (USD $)	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2013 Source	Dec. 31, 2012 Source
Fair Value Measurements Disclosure [Line Items]
Number of independent sources for market quotes		2	2
Unrealized gain/loss on derivative instruments	$ 420,000
U.S. Treasury Note maturity date	Nov. 15, 2021
Discounting expected future cash flow at market rate		31,400,000	8,000,000
Greenfield [Member]
Fair Value Measurements Disclosure [Line Items]
Fair Value of Investments		15,500,000	15,600,000
Calamar Enterprises, Inc. [Member]
Fair Value Measurements Disclosure [Line Items]
Fair Value of Investments		17,700,000
NACAL, LLC and RECAL LLC [Member]
Fair Value Measurements Disclosure [Line Items]
Fair Value of notes receivable		2,600,000
10-Year U.S. Treasury Note (short sale) [Member] | US Treasury Notes Securities [Member]
Fair Value Measurements Disclosure [Line Items]
Unrealized gain realized	$ 100,000