Fair Value Measurements (Details 7) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$ 161,020	$ 164,757
Interest-earning deposits in financial institutions	235,466	148,469
Available-for-sale Securities	3,559,437	1,567,177
Federal Home Loan Bank stock, at cost	19,710	40,609
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	19,710	40,609
Cost Method Investments	2,267	3,691
Cost Method Investments, Fair Value Disclosure	6,789	3,691
Equity Method Investments		21,461
Equity Method Investments, Fair Value Disclosure		21,700
Loans and leases, net	14,363,143	11,797,977
Loans Receivable, Fair Value Disclosure	14,393,558
Derivative Asset	11,919	5,234
Warrants Not Settleable in Cash, Fair Value Disclosure	4,914
Deposits, Savings Deposits	11,513,826	6,256,190
Time Deposits	4,152,356	5,498,938
Deposits, Fair Value Disclosure	4,152,920	5,502,479
Borrowings	621,914	383,402
Borrowed Funds		383,402
Long-term Debt, Fair Value	622,438	383,539
Subordinated debentures	436,000	433,583
Subordinated Debt Obligations, Fair Value Disclosure	419,762	417,657
Derivative Liability		118
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	161,020	164,757
Interest-earning deposits in financial institutions	235,466	148,469
Available-for-sale Securities		519
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	0	0
Cost Method Investments, Fair Value Disclosure	0	0
Equity Method Investments, Fair Value Disclosure		0
Deposits, Savings Deposits	0	0
Deposits, Fair Value Disclosure	0	0
Long-term Debt, Fair Value	618,000	380,000
Subordinated Debt Obligations, Fair Value Disclosure	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0	0
Interest-earning deposits in financial institutions	0	0
Available-for-sale Securities		1,532,711
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	19,710	40,609
Cost Method Investments, Fair Value Disclosure	0	0
Equity Method Investments, Fair Value Disclosure		0
Deposits, Savings Deposits	11,513,826	6,256,190
Deposits, Fair Value Disclosure	4,152,920	5,502,479
Long-term Debt, Fair Value	4,438	3,539
Subordinated Debt Obligations, Fair Value Disclosure	419,762	417,657
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0	0
Interest-earning deposits in financial institutions	0	0
Available-for-sale Securities		33,947
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	0	0
Cost Method Investments, Fair Value Disclosure	6,789	3,691
Equity Method Investments, Fair Value Disclosure		21,700
Loans Receivable, Fair Value Disclosure	14,384,191
Deposits, Savings Deposits	0	0
Deposits, Fair Value Disclosure	0	0
Long-term Debt, Fair Value	0	0
Subordinated Debt Obligations, Fair Value Disclosure	0	0
NonPCI and PCI Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases, net	14,363,143	11,797,977
Loans Receivable, Fair Value Disclosure		11,757,951
NonPCI and PCI Loans [Member] | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure		0
NonPCI and PCI Loans [Member] | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure		2,366
NonPCI and PCI Loans [Member] | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure		11,755,585
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities	3,559,437	1,567,177
Derivative Asset, Fair Value of Collateral	11,919	5,234
Derivative Liability, Fair Value of Collateral	1,397	118
Fair Value, Measurements, Recurring [Member] | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities	71,942	519
Derivative Asset, Fair Value of Collateral	0	0
Warrants Not Settleable in Cash, Fair Value Disclosure	0
Derivative Liability, Fair Value of Collateral	0	0
Fair Value, Measurements, Recurring [Member] | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities	3,388,054	1,532,711
Derivative Asset, Fair Value of Collateral	11,919	5,234
Warrants Not Settleable in Cash, Fair Value Disclosure	0
Derivative Liability, Fair Value of Collateral	1,397	118
Fair Value, Measurements, Recurring [Member] | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities	99,441	33,947
Derivative Asset, Fair Value of Collateral	0	0
Warrants Not Settleable in Cash, Fair Value Disclosure	4,914
Derivative Liability, Fair Value of Collateral	0	$ 0
Non Purchased Credit Impaired Loans and Leases [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	0
Non Purchased Credit Impaired Loans and Leases [Member] | Fair Value, Measurements, Nonrecurring [Member] | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	$ 9,367