XML 44 R55.htm IDEA: XBRL DOCUMENT v3.19.3

Non-Marketable Equity Investments - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Investments Debt And Equity Securities [Abstract]
Reduction to carrying value of non-marketable equity investment due to downward change in fair value	$ 1,271
Aggregate carrying amount of non-marketable equity investments		$ 5,400	$ 2,100

X

- Definition

Change in fair value of non-marketable equity investments.

+ References

No definition available.

+ Details

Name:	hstm_ChangeInFairValueOfNonMarketableEquityInvestments
Namespace Prefix:	hstm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=116654751&loc=SL75117539-209714

+ Details

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

X

- References

No definition available.

+ Details

Name:	us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration