Consolidated Statement of Changes in Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2013	$ 1,041,732	$ 127,169	$ 237,674	$ 734,945	$ (43,047)	$ (15,009)
Beginning Balance, shares at Dec. 31, 2013		50,867,630
Comprehensive income:
Net income	96,631	0	0	96,631	0	0
Other comprehensive income, net of tax:	19,377	0	0	0	19,377	0
Comprehensive income, net of tax	116,008
Stock based compensation expense	1,593	0	1,593	0	0	0
Acquisition of Virginia Commerce Bancorp, Inc. (18,330,347 shares)	552,262	45,826	506,436	0	0	0
Acquisition of Virginia Commerce Bancorp, Inc., shares		18,330,347
Distribution of treasury stock for deferred compensation plan (3,637 shares)	81	0	0	0	0	81
Purchase of treasury stock (726 shares)	(25)	0	0	0	0	(25)
Cash dividends ($0.96 per share)	(66,357)	0	0	(66,357)	0	0
Grant of restricted stock (66,949 shares)	0	0	(2,305)	0	0	2,305
Forfeiture of restricted stock (2,338 shares)	0	0	81	0	0	(81)
Common stock options exercised (368,856 shares)	8,379	66	(3,476)	0	0	11,789
Common stock options exercised, shares	368,856	26,474				342,382
Ending Balance at Sep. 30, 2014	$ 1,653,673	$ 173,061	$ 740,003	$ 765,219	$ (23,670)	$ (940)
Ending Balance, shares at Sep. 30, 2014		69,224,451