Fair Value - Level 3 Assets (Details) - Level 3 - Available-for-sale securities - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	$ 8,924	$ 11,120	$ 12,577	$ 10,079
Included in earnings	10	3	18	4
Included in other comprehensive income	(90)	71	208	30
Purchases	2,849	2,444	4,982	5,491
Sales	(510)	(1,416)	(7,879)	(2,381)
Transfers into Level 3	4,696	2,735	15,347	10,517
Transfers out of Level 3	(1,814)	(5,782)	(11,188)	(14,565)
Ending balance	14,065	9,175	14,065	9,175
Change in unrealized gains or losses included in other comprehensive income related to Level 3 securities held at the reporting date
Change in unrealized gains or losses included in other comprehensive income related to Level 3 securities	(93)	66	244	38
Corporate debt securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	6,373	11,120	12,577	7,879
Included in earnings	16	3	7	4
Included in other comprehensive income	(92)	71	199	23
Purchases	549	1,539	1,283	4,586
Sales	(507)	(1,416)	(6,779)	(2,381)
Transfers into Level 3	1,850	2,735	9,244	10,517
Transfers out of Level 3	(1,131)	(5,782)	(9,473)	(12,358)
Ending balance	7,058	8,270	7,058	8,270
Change in unrealized gains or losses included in other comprehensive income related to Level 3 securities held at the reporting date
Change in unrealized gains or losses included in other comprehensive income related to Level 3 securities	(100)	66	112	38
Residential mortgage-backed securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance			0
Included in earnings			4
Included in other comprehensive income			15
Purchases			921
Sales			(32)
Transfers into Level 3			0
Transfers out of Level 3			(908)
Ending balance	0		0
Commercial mortgage-backed securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	2,551		0
Included in earnings	(6)		7
Included in other comprehensive income	2		(6)
Purchases	0		478
Sales	(3)		(1,068)
Transfers into Level 3	2,846		6,103
Transfers out of Level 3	(683)		(807)
Ending balance	4,707		4,707
Change in unrealized gains or losses included in other comprehensive income related to Level 3 securities held at the reporting date
Change in unrealized gains or losses included in other comprehensive income related to Level 3 securities	7	0	132	0
Collateralized debt obligations
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	0		0	2,200
Included in earnings	0		0	0
Included in other comprehensive income	0		0	7
Purchases	2,300		2,300	0
Sales	0		0	0
Transfers into Level 3	0		0	0
Transfers out of Level 3	0		0	(2,207)
Ending balance	2,300	0	2,300	0
Other debt securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance		0		0
Included in earnings		0		0
Included in other comprehensive income		0		0
Purchases		905		905
Sales		0		0
Transfers into Level 3		0		0
Transfers out of Level 3		0		0
Ending balance		905		905
Change in unrealized gains or losses included in other comprehensive income related to Level 3 securities held at the reporting date
Change in unrealized gains or losses included in other comprehensive income related to Level 3 securities	$ 0	$ 0	$ 0	$ 0

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- Definition

Amount of unrealized gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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-Publisher FASB
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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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