Pending Acquisitions - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Business Acquisition [Line Items]
Common stock number of shares issued for consideration	2,000,000
Amount of cash consideration	$ 220
Period used to determine volume weighted average price of shares issued in the merger	10 days
Targeted Shareholders' Equity At Closing	$ 87
Jack Wood [Member]
Business Acquisition [Line Items]
Holding period of common stock received in merger	1 year
Donald Wood [Member]
Business Acquisition [Line Items]
Holding period of common stock received in merger	6 months