Investments - Amortized Cost and Fair Value of Securities Available for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Available for sale:
Amortized Cost	$ 182,325	$ 247,607
Gross Unrealized Gains	178	650
Gross Unrealized Losses	(6,258)	(4,169)
Estimated Fair Value	176,245	244,088
Mortgage-backed securities
Available for sale:
Amortized Cost	159,937	227,607
Gross Unrealized Gains	155	650
Gross Unrealized Losses	(5,517)	(3,210)
Estimated Fair Value	154,575	225,047
Utah Housing Corporation bonds
Available for sale:
Amortized Cost	22,388	20,000
Gross Unrealized Gains	23	0
Gross Unrealized Losses	(741)	(959)
Estimated Fair Value	$ 21,670	$ 19,041

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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-Publisher FASB
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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
-Paragraph 2
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
-Paragraph 1
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