Related Party Transactions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended			3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2011 Board of Directors Chairman	Dec. 31, 2011 Board of Directors Chairman Airplane	Dec. 31, 2011 Board of Directors Chairman Vehicle
Related Party Transaction [Line Items]
Purchase of airplane	$ 58,145	$ 65,073	$ 78,211
Related party transaction amount					2,800	21
Brokerage fees paid				$ 80