Fair Value Measurements (Details 6) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 544,658	$ 161,215
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	55,952	148,330
Non Purchased Credit Impaired Loans and Leases [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	61,095	149,749
Non Purchased Credit Impaired Loans and Leases [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	55,952	148,088
Cost-method Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		242
Cost-method Investments [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring		$ 242
Discount Rates [Member] | Discounted Cash Flow [Member] | Non Purchased Credit Impaired Loans and Leases [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 41,984
Discount Rates [Member] | Minimum [Member] | Discounted Cash Flow [Member] | Non Purchased Credit Impaired Loans and Leases [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	2.00%
Discount Rates [Member] | Maximum [Member] | Discounted Cash Flow [Member] | Non Purchased Credit Impaired Loans and Leases [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	10.20%
Discount Rates [Member] | Weighted Average [Member] | Discounted Cash Flow [Member] | Non Purchased Credit Impaired Loans and Leases [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate	7.43%
No Discounts [Member] | Third party appraisals [Domain] | Non Purchased Credit Impaired Loans and Leases [Member] | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$ 13,968