Business Combination - Earnout Agreement (Details) - $ / shares	Mar. 15, 2019	Dec. 31, 2019
Common shares placed into escrow	5,015,898	5,015,898
Scenario if share price exceeds $12.50
Period after business combination to release shares from escrow account	3 years
Share price	$ 12.50
Number of trading days to monitor share price to release shares from escrow account	20 days
Number of consecutive trading days to monitor share price to release shares from escrow account	30 days
Percentage of founder shares to be released from escrow account	50.00%
Scenario if share price exceeds $15.00
Period after business combination to release shares from escrow account	3 years
Share price	$ 15.00
Number of trading days to monitor share price to release shares from escrow account	20 days
Number of consecutive trading days to monitor share price to release shares from escrow account	30 days
Percentage of founder shares to be released from escrow account	50.00%

Represents the number of common shares placed into escrow.

No definition available.

Name:	th_CommonSharesPlacedIntoEscrow
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Data Type:	xbrli:sharesItemType
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Period Type:	instant

Represents the number of consecutive trading days to monitor share price to release shares from escrow account.

No definition available.

Name:	th_NumberOfConsecutiveTradingDaysToMonitorSharePriceToReleaseSharesFromEscrowAccount
Namespace Prefix:	th_
Data Type:	xbrli:durationItemType
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Period Type:	duration

Represents the number of trading days to monitor share price to release shares from escrow account.

No definition available.

Name:	th_NumberOfTradingDaysToMonitorSharePriceToReleaseSharesFromEscrowAccount
Namespace Prefix:	th_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of founder shares to be released from escrow account.

No definition available.

Name:	th_PercentageOfFounderSharesToBeReleasedFromEscrowAccount
Namespace Prefix:	th_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents period of time after business combination when the escrow shares should be issued or cancelled.

No definition available.

Name:	th_PeriodAfterBusinessCombinationToReleaseSharesFromEscrowAccount
Namespace Prefix:	th_
Data Type:	xbrli:durationItemType
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Period Type:	duration

Price of a single share of a number of saleable stocks of a company.

No definition available.

Name:	srt_StatementScenarioAxis=th_ScenarioIfSharePriceExceeds12.50Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_StatementScenarioAxis=th_ScenarioIfSharePriceExceeds15.00Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: