Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Fair Value Measurements (Textual) [Abstract]
Impaired loans not covered under loss-share agreements	$ 9,521		$ 22,621
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Specific reserve included in allowance for loan losses	49,835		49,026
Changes in fair value, gain (loss)	(769)	$ 1,437
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	$ 969		$ 935