Investments - Investments in Variable Interest Entities (Parenthetical) (Detail) (USD $)				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Aqua [Member]	Dec. 31, 2013 ELX [Member]	Mar. 28, 2012 ELX [Member]
Variable Interest Entity [Line Items]
Credit agreement commitment to variable interest entity				$ 16,000,000	$ 16,000,000
Credit facility commitment period				Mar. 28, 2015
Principal sum of loan due from related parties	$ 15,211,000	$ 21,655,000	$ 980,000