Fair Value Measurements - Level 3 Assets, Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	$ 68,379	$ 63,572
Impaired originated loans
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	65,565	62,184
Other real estate/repossessed assets
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	2,814	1,386
Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	68,379	63,572
Level 3 | Impaired originated loans
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	$ 65,565	62,184
Level 3 | Impaired originated loans | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	10.00%
Level 3 | Impaired originated loans | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	25.00%
Level 3 | Other real estate/repossessed assets
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	$ 2,814	$ 1,386
Level 3 | Other real estate/repossessed assets | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	10.00%
Level 3 | Other real estate/repossessed assets | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	25.00%