Fair Value Measurements - (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Fair Value Measurements (Textual) [Abstract]
Impaired loans not covered under loss-share agreements	$ 7,409,000	$ 7,409,000		$ 7,191,000
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Specific reserve included in allowance for loan losses	44,098,000	44,098,000		42,437,000
Impairment losses on mortgage servicing rights	40,000	40,000	$ 0
Changes in fair value, gain (loss)		6,172,000	$ (178,000)
Impaired Loans, Not Covered
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Specific reserve included in allowance for loan losses	$ 795,000	$ 795,000		$ 683,000