Accumulated Other Comprehensive Income - Changes, net of tax, in Accumulated other comprehensive income are as follows (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	$ 6,516
Other comprehensive income	4,164
Balance at end of period	10,680
Unrealized Gains on Securities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	6,921
Other comprehensive income	4,134
Balance at end of period	11,055
Cumulative Translation Adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	(405)
Other comprehensive income	30
Balance at end of period	$ (375)