XML 82 R47.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Summary of Significant Accounting Policies - Concentration of Risk (Details) - customer	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue | Customer concentration risk
Concentration of Risk
Number of customers	3	2	2
Revenue | Customer concentration risk | Ten largest customers
Concentration of Risk
Number of customers	10	10	10
Percentage of concentration risk	74.10%	76.90%	73.30%
Revenue | Customer concentration risk | First customer
Concentration of Risk
Percentage of concentration risk	18.20%	20.10%	24.90%
Revenue | Customer concentration risk | Second customer
Concentration of Risk
Percentage of concentration risk	14.20%	12.10%	13.10%
Revenue | Customer concentration risk | Third customer
Concentration of Risk
Percentage of concentration risk	12.00%
Consolidated accounts receivable | Credit concentration risk
Concentration of Risk
Number of customers	3	2
Consolidated accounts receivable | Credit concentration risk | First customer
Concentration of Risk
Percentage of concentration risk	24.90%	21.90%
Consolidated accounts receivable | Credit concentration risk | Second customer
Concentration of Risk
Percentage of concentration risk	15.30%	11.50%
Consolidated accounts receivable | Credit concentration risk | Third customer
Concentration of Risk
Percentage of concentration risk	11.10%

X

- Definition

Represents the number of customers on whom the entity significantly relies giving rise to concentration risk.

+ References

No definition available.

+ Details

Name:	acls_ConcentrationRiskNumberOfCustomers
Namespace Prefix:	acls_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

X

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=acls_TenLargestCustomersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=acls_LargestCustomerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=acls_SecondLargestCustomerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=acls_ThirdLargestCustomerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CreditConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: