Acquisitions (Textual) (Details) (USD $)	3 Months Ended			0 Months Ended		0 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 07, 2012 Independent Bank [Member] Branches	Dec. 07, 2012 Independent Bank [Member] Core Deposits [Member]	Apr. 30, 2010 OAK [Member] Offices	Mar. 31, 2014 OAK [Member]	Dec. 31, 2013 OAK [Member]	Mar. 31, 2013 OAK [Member]
Business Acquisition [Line Items]
Number of branches acquired (branches)				21
Deposits acquired				$ 404,000,000
Loans acquired				44,000,000		627,000,000
Acquisition purchase price				8,100,000		83,700,000
Premium paid on deposits purchased				11,500,000
Premium paid as a percentage of deposits purchased (percent)				2.85%
Discount on loans purchased (percent)				1.75%
Goodwill	120,164,000	120,164,000	120,164,000	6,800,000
Intangibles acquired					5,600,000
Service provided by acquiree bank through number of branches						14
Assets of acquiree company						820,000,000
Deposits of acquiree company						693,000,000
Brokered deposits of acquiree company						193,000,000
Contractually required principal payments of loan portfolio, acquisition date						683,000,000
Acquired loan portfolio acquisition date fair value						627,000,000
Outstanding contractual principal balance of acquired loan portfolio							313,000,000	320,000,000	400,000,000
Carrying amount of acquired loan portfolio							289,000,000	295,000,000	374,000,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	$ 10,000,000	$ 125,000