CASH, CASH EQUIVALENTS, AND INVESTMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	$ 280,293	$ 301,970	$ 242,461	$ 235,266
Short-term investments (due in 1 year or less)	218,773	178,179
Long-term investments (due in 1 to 3 years)	118,870	127,176
Total cash, cash equivalents and investments measured at fair value, amortized cost	618,426	607,374
Total cash, cash equivalents and investments measured at fair value, gross unrealized gains	444	439
Total cash, cash equivalents and investments measured at fair value, gross unrealized losses	(934)	(488)
Total cash, cash equivalents and investments measured at fair value, fair value	617,936	607,325
Cash [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	272,063	295,877
Level 1 [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	5,237	0
Available-for-sale Securities, amortized cost basis	86,221	48,039
Available-for-sale Securities, gross unrealized gains	399	352
Available-for-sale Securities, gross unrealized losses	(280)	(100)
Available-for-sale Securities, fair value	86,340	48,291
Short-term investments (due in 1 year or less)	56,975	29,959
Long-term investments (due in 1 to 3 years)	24,128	18,332
Level 1 [Member] \| Mutual Funds [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Available-for-sale Securities, amortized cost basis	14,298	12,079
Available-for-sale Securities, gross unrealized gains	399	352
Available-for-sale Securities, gross unrealized losses	(70)	(32)
Available-for-sale Securities, fair value	14,627	12,399
Short-term investments (due in 1 year or less)	14,627	12,399
Long-term investments (due in 1 to 3 years)	0	0
Level 1 [Member] \| US Treasury Notes [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	4,998	0
Available-for-sale Securities, amortized cost basis	71,684	35,960
Available-for-sale Securities, gross unrealized gains	0	0
Available-for-sale Securities, gross unrealized losses	(210)	(68)
Available-for-sale Securities, fair value	71,474	35,892
Short-term investments (due in 1 year or less)	42,348	17,560
Long-term investments (due in 1 to 3 years)	24,128	18,332
Level 1 [Member] \| Money Market Funds [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	239	0
Available-for-sale Securities, amortized cost basis	239	0
Available-for-sale Securities, gross unrealized gains	0	0
Available-for-sale Securities, gross unrealized losses	0	0
Available-for-sale Securities, fair value	239	0
Level 2 [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	2,993	6,093
Available-for-sale Securities, amortized cost basis	260,142	263,458
Available-for-sale Securities, gross unrealized gains	45	87
Available-for-sale Securities, gross unrealized losses	(654)	(388)
Available-for-sale Securities, fair value	259,533	263,157
Short-term investments (due in 1 year or less)	161,798	148,220
Long-term investments (due in 1 to 3 years)	94,742	108,844
Level 2 [Member] \| Government Agency Securities [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Available-for-sale Securities, amortized cost basis	56,667	54,415
Available-for-sale Securities, gross unrealized gains	0	20
Available-for-sale Securities, gross unrealized losses	(276)	(164)
Available-for-sale Securities, fair value	56,391	54,271
Short-term investments (due in 1 year or less)	31,300	15,309
Long-term investments (due in 1 to 3 years)	25,091	38,962
Level 2 [Member] \| Commercial Paper [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	2,993	6,093
Available-for-sale Securities, amortized cost basis	32,944	47,152
Available-for-sale Securities, gross unrealized gains	0	0
Available-for-sale Securities, gross unrealized losses	0	0
Available-for-sale Securities, fair value	32,944	47,152
Short-term investments (due in 1 year or less)	29,951	41,059
Long-term investments (due in 1 to 3 years)	0	0
Level 2 [Member] \| Corporate Bonds [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Available-for-sale Securities, amortized cost basis	142,148	141,508
Available-for-sale Securities, gross unrealized gains	45	64
Available-for-sale Securities, gross unrealized losses	(375)	(224)
Available-for-sale Securities, fair value	141,818	141,348
Short-term investments (due in 1 year or less)	77,175	73,676
Long-term investments (due in 1 to 3 years)	64,643	67,672
Level 2 [Member] \| Certificates of Deposit [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Available-for-sale Securities, amortized cost basis	28,383	20,383
Available-for-sale Securities, gross unrealized gains	0	3
Available-for-sale Securities, gross unrealized losses	(3)	0
Available-for-sale Securities, fair value	28,380	20,386
Short-term investments (due in 1 year or less)	23,372	18,176
Long-term investments (due in 1 to 3 years)	$ 5,008	$ 2,210

Cash, Cash Equivalents, Short-term and Long-term Investments, Amortized Cost

No definition available.

Name:	plt_CashCashEquivalentsShorttermandLongtermInvestmentsAmortizedCost
Namespace Prefix:	plt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cash, Cash Equivalents, Short-term and Long-term Investments, Fair Value

+ References

No definition available.

+ Details

Name:	plt_CashCashEquivalentsShorttermandLongtermInvestmentsFairValue
Namespace Prefix:	plt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Cash, Cash Equivalents, Short-term and Long-term Investments, Gross Unrealized Gain

+ References

No definition available.

+ Details

Name:	plt_CashCashEquivalentsShorttermandLongtermInvestmentsGrossUnrealizedGain
Namespace Prefix:	plt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Cash, Cash Equivalents, Short-term and Long-term Investments, Gross Unrealized Loss

+ References

No definition available.

+ Details

Name:	plt_CashCashEquivalentsShorttermandLongtermInvestmentsGrossUnrealizedLoss
Namespace Prefix:	plt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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:	plt_ScheduleOfCashCashEquivalentsAndInvestmentsLineItems
Namespace Prefix:	plt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=75030427&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26610-111562

+ Details

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

- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

+ Details

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

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

+ Details

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

- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3044-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).

+ References

+ Details

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

- Definition

Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(g))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(5))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_CashMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=plt_MutualFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: