Securities Available for Sale - Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amortized cost
Within 1 year	$ 46,458
After 1 year through 5 years	4,319
Amortized Cost	271,173	$ 170,189
Fair value
Within 1 year	46,470
After 1 year through 5 years	4,322
Fair Value	270,927	170,469
Corporate debt securities
Amortized cost
Within 1 year	14,333
Amortized Cost	14,333	17,339
Fair value
Within 1 year	14,343
Fair Value	14,343	17,328
Certificates of deposit
Amortized cost
Within 1 year	13,100
Amortized Cost	13,100	14,929
Fair value
Within 1 year	13,100
Fair Value	13,100	14,929
Other asset-backed securities
Amortized cost
Within 1 year	7,756
After 1 year through 5 years	4,319
Amortized Cost	12,075	11,232
Fair value
Within 1 year	7,758
After 1 year through 5 years	4,322
Fair Value	12,080	11,225
Commercial paper
Amortized cost
Within 1 year	9,274
Amortized Cost	9,274	9,720
Fair value
Within 1 year	9,274
Fair Value	9,274	$ 9,720
U.S. agency securities
Amortized cost
Within 1 year	1,995
Amortized Cost	1,995
Fair value
Within 1 year	1,995
Fair Value	1,995
Asset-backed securities related to structured program transaction
Amortized cost
Amortized Cost	220,396
Fair value
Fair Value	$ 220,135

Amortized cost 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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-Publisher FASB
-Name Accounting Standards Codification
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