Summary of Significant Accounting Policies - Components of Accumulated Other Comprehensive (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Comprehensive Income Loss Tax Parenthetical Disclosures [Abstract]
Tax on Unrealized loss/ gain on investments before reclassification	$ 41	$ 7	$ 41
Tax on Reclassification adjustment for net gains/ losses realized in net income	$ 691	$ 12	$ 8