Common Stock - Share Repurchase of Common Stock (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			240 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Statement Of Stockholders Equity [Abstract]
Number of Shares	581,387	285,495	1,017,588	23,300,000
Aggregate Purchase Price	$ 554,491	$ 227,281	$ 689,302	$ 5,308,000