Income Taxes - Net Deferred Tax Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Net deferred tax assets
Net deferred tax assets	$ 27,747	$ 24,302
Valuation allowance for deferred tax assets	$ 0	$ 0

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b),(c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

Name:	us-gaap_DeferredTaxAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant