Loans and the Allowance for Loan Losses (Details 12) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Investment in loans, net of unearned income on impairment methodology
Individually evaluated for impairment	$ 56,853		$ 64,868
Collectively evaluated for impairment	3,342,599		2,497,356
Acquired with deteriorated credit quality	482,080		248,029
Loans, net of unearned income	3,881,532		2,810,253
Commercial [Member]
Investment in loans, net of unearned income on impairment methodology
Individually evaluated for impairment	771		1,620
Collectively evaluated for impairment	443,991		304,290
Acquired with deteriorated credit quality	36,481		11,140
Loans, net of unearned income	481,243		317,050
Real Estate - Construction [Member]
Investment in loans, net of unearned income on impairment methodology
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	146,334		104,058
Acquired with deteriorated credit quality	5,883		1,648
Loans, net of unearned income	152,217		105,706
Real Estate - 1-4 Family Mortgage [Member]
Investment in loans, net of unearned income on impairment methodology
Individually evaluated for impairment	25,537		28,848
Collectively evaluated for impairment	1,058,353		799,428
Acquired with deteriorated credit quality	108,333		75,147
Loans, net of unearned income	1,192,223		903,423
Real estate - commercial mortgage [Member]
Investment in loans, net of unearned income on impairment methodology
Individually evaluated for impairment	30,545		34,400
Collectively evaluated for impairment	1,606,176		1,234,374
Acquired with deteriorated credit quality	323,863		157,869
Loans, net of unearned income	1,960,584		1,426,643
Installment and Other [Member]
Investment in loans, net of unearned income on impairment methodology
Individually evaluated for impairment	0	[1]	0	[1]
Collectively evaluated for impairment	87,745	[1]	55,206	[1]
Acquired with deteriorated credit quality	7,520	[1]	2,225	[1]
Loans, net of unearned income	$ 95,265	[1]	$ 57,431	[1]

[1] Includes lease financing receivables.