Restructuring and other impairment charges - reconciliation of changes in accrued liabilities associated with restructuring program (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
2018 Footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	$ 0
Subsequent accruals	54,993
Cash payments	(4,503)
Foreign currency translation	(2,016)
Balance, ending	48,474	$ 0
2016 Footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	7,665	8,895
Subsequent accruals	2,861	2,097
Cash payments	(4,866)	(3,314)
Foreign currency translation	(244)	(13)
Balance, ending	5,416	7,665
2014 Manufacturing footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	3,926	5,370
Subsequent accruals	830	755
Cash payments	(820)	(2,199)
Balance, ending	3,936	3,926
Termination benefits \| 2018 Footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	0
Subsequent accruals	53,992
Cash payments	(3,503)
Foreign currency translation	(2,015)
Balance, ending	48,474	0
Termination benefits \| 2016 Footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	7,296	8,135
Subsequent accruals	2,318	1,314
Cash payments	(3,954)	(2,096)
Foreign currency translation	(244)	(57)
Balance, ending	5,416	7,296
Termination benefits \| 2014 Manufacturing footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	3,926	5,370
Subsequent accruals	744	687
Cash payments	(734)	(2,131)
Balance, ending	3,936	3,926
Other Costs \| 2018 Footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	0
Subsequent accruals	1,001
Cash payments	(1,000)
Foreign currency translation	(1)
Balance, ending	0	0
Other Costs \| 2016 Footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	369	760
Subsequent accruals	543	783
Cash payments	(912)	(1,218)
Foreign currency translation	0	44
Balance, ending	0	369
Other Costs \| 2014 Manufacturing footprint realignment plan
Restructuring Reserve [Roll Forward]
Balance, beginning	0	0
Subsequent accruals	86	68
Cash payments	(86)	(68)
Balance, ending	$ 0	$ 0

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3367-108585

+ Details

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

- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

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

- Definition

Amount of expense (reversal of expense) which increases (decreases) the restructuring reserve from an adjustment to a previously accrued restructuring liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b)(2))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringReserveAccrualAdjustment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount of foreign currency translation gain (loss) which decreases (increases) the restructuring reserve.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b)(2))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

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

- Details

Name:	us-gaap_RestructuringPlanAxis=tfx_TwoThousandEighteenFootprintRealignmentPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=tfx_A2016ManufacturingFootprintRealignmentPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=tfx_TwoThousandFourteenManufacturingFootprintRealignmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_SpecialTerminationBenefitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_OtherRestructuringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: