Fair Value Measurements - (Table of Valuation Techniques and Unobservable Inputs Used in Valuation of Financial Instruments Falling Within Level 3 of Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets at fair value	$ 822,779	$ 895,262
Impaired loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets at fair value	$ 28,459
Minimum | Appraised value [Member] | Impaired loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Appraised values Discount rate	0.00%
Maximum | Appraised value [Member] | Impaired loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Appraised values Discount rate	25.00%