Note 15 - Concentration of Risk (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale, Realized Gain	$ 7,000
Debt Securities, Available-for-sale, Realized Loss	$ 57,000
Accounts Receivable [Member] \| Customer Concentration Risk [Member]
Concentration Risk Threshold Percentage	10.00%	10.00%
Sales Revenue, Net [Member] \| Customer Concentration Risk [Member]
Concentration Risk Threshold Percentage	10.00%	10.00%

The concentration risk threshold percentage derived from quantitative amount.

No definition available.

Name:	apt_ConcentrationRiskThresholdPercentage
Namespace Prefix:	apt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleRealizedGain
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleRealizedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

- Details

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

- Details

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