Mergers and Acquisition - Additional Information (Detail) (USD $)			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Virginia Commerce Bancorp, Inc. [Member]	Jan. 31, 2014 Subsequent [Member]	Dec. 31, 2013 Centra Financial Holdings Inc [Member]
Outstanding common stock acquired				100.00%
Total assets at consummation	$ 8,735,324,000	$ 8,420,013,000			$ 2,770,000,000
Loans at consummation	6,713,599,000	6,517,780,000			2,100,000,000
Deposits at consummation	6,621,571,000	6,752,986,000			2,020,000,000
Common stock, par value	$ 2.50	$ 2.50	$ 1.00
Outstanding share of common stock			0.5442
Issue of common stock			18,300,000
Issue of options to purchase upon conversion of Commerce's stock options			441,000
Common stock paid in cash			8,000
Warrant held and purchased by TARP Capital Purchase Program			$ 33,263,000