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Securities, HTM Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Mar. 31, 2019 USD ($) Position	Dec. 31, 2018 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 23,293
12 months or longer	226,992	286,233
Total	226,992	309,526
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	(91)
12 months or longer	(3,571)	(8,195)
Total	$ (3,571)	$ (8,286)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	0	32
12 months or longer | Position	60	118
Total | Position	60	150
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 0
12 months or longer	82,204	82,579
Total	82,204	82,579
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	0
12 months or longer	(981)	(2,773)
Total	$ (981)	$ (2,773)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	0	0
12 months or longer | Position	6	6
Total | Position	6	6
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 4,386
12 months or longer	125,486	145,396
Total	125,486	149,782
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	(7)
12 months or longer	(2,230)	(3,890)
Total	$ (2,230)	$ (3,897)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	0	2
12 months or longer | Position	24	26
Total | Position	24	28
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 18,907
12 months or longer	19,302	58,258
Total	19,302	77,165
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	(84)
12 months or longer	(360)	(1,532)
Total	$ (360)	$ (1,616)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	0	30
12 months or longer | Position	30	86
Total | Position	30	116

X

- Definition

Number of investment positions in held-to-maturity investments in a continuous unrealized loss position for greater than or equal to a year for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer.

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

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Disclosure regarding factors used to determine that the impairment of securities categorized as held-to-maturity where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the held-to-maturity investments determined to be temporarily impaired.

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