Commitments and Contingencies (Details) (Special Long-Term Retention and Incentive Cash Awards Program, USD $) In Millions, unless otherwise specified	12 Months Ended	3 Months Ended	1 Months Ended
Dec. 31, 2011	Mar. 31, 2014 Cash bonus expense	May 31, 2014 Cash bonus expense Subsequent events
Special Long-Term Retention and Incentive Cash Awards Program
Timeframe for achievement of performance conditions	6 years
Maximum compensation expense to be recognized if sufficient performance conditions are achieved		$ 38.2
Compensation expenses related to cash bonus to be recognized in next fiscal year if sufficient performance conditions are achieved			5.0
Compensation expenses related to cash bonus recognized in current year given sufficient performance conditions achieved		9.1
Vesting period			1 year
Total Cash bonus expense related to grant subject to performance conditions		$ 9.5

Aggregate cost of compensation made to employees under long-term retention program during the current fiscal year.

No definition available.

Name:	thrx_LongTermRetentionProgramCashBonusExpenseRecognized
Namespace Prefix:	thrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Vesting period of cash bonus expenses to be recognized under long-term retention program.

+ References

No definition available.

+ Details

Name:	thrx_LongTermRetentionProgramCashBonusExpenseToBeRecognizedOverVestingPeriod
Namespace Prefix:	thrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of the entity's long-term retention program, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	thrx_LongTermRetentionProgramPeriod
Namespace Prefix:	thrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate potential maximum cost of compensation made to employees under long-term retention program.

+ References

No definition available.

+ Details

Name:	thrx_LongTermRetentionProgramPotentialMaximumTotalCompensationCost
Namespace Prefix:	thrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate potential maximum cost of compensation made to employees under long term retention program that may be recognized in the next fiscal year.

+ References

No definition available.

+ Details

Name:	thrx_LongTermRetentionProgramPotentialMaximumTotalCompensationCostInNextFiscalYear
Namespace Prefix:	thrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate cost of compensation made to employees under long-term retention program during the current fiscal year.

+ References

No definition available.

+ Details

Name:	thrx_TotalLongTermRetentionProgramCashBonusExpenseRecognized
Namespace Prefix:	thrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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