Investments - Amortized Cost and Fair Value of Securities Available for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 331,519	$ 182,325
Gross Unrealized Gains	1,537	178
Gross Unrealized Losses	(1,515)	(6,258)
Available-for-sale investments	331,541	176,245
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	233,210	159,937
Gross Unrealized Gains	1,196	155
Gross Unrealized Losses	(1,445)	(5,517)
Available-for-sale investments	232,961	154,575
Utah Housing Corporation bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	21,136	22,388
Gross Unrealized Gains	181	23
Gross Unrealized Losses	(70)	(741)
Available-for-sale investments	21,247	$ 21,670
U.S. government-sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	77,173
Gross Unrealized Gains	160
Gross Unrealized Losses	0
Available-for-sale investments	$ 77,333

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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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).

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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
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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).

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