Annual report pursuant to Section 13 and 15(d)

Other Income (Expense) (Details)

v2.4.1.9
Other Income (Expense) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2013
Foreign Currency Transaction Gain (Loss), before Tax $ (695)us-gaap_ForeignCurrencyTransactionGainLossBeforeTax $ (304)us-gaap_ForeignCurrencyTransactionGainLossBeforeTax $ (426)us-gaap_ForeignCurrencyTransactionGainLossBeforeTax
Other (71)thr_OtherNonoperatingIncomeExpenseOther 17thr_OtherNonoperatingIncomeExpenseOther 98thr_OtherNonoperatingIncomeExpenseOther
Other Nonoperating Expense (394)us-gaap_OtherNonoperatingExpense (596)us-gaap_OtherNonoperatingExpense (325)us-gaap_OtherNonoperatingExpense
Foreign Exchange Forward Contracts [Member]      
Gain (Loss) on Foreign Currency Derivatives Recorded in Earnings, Net (559)us-gaap_GainLossOnForeignCurrencyDerivativesRecordedInEarningsNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
(309)us-gaap_GainLossOnForeignCurrencyDerivativesRecordedInEarningsNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
3us-gaap_GainLossOnForeignCurrencyDerivativesRecordedInEarningsNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
CHS Transactions [Member]      
Gain on settlement of related party transactions $ 931thr_GainonSettlementofRelatedPartyTransactions
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= thr_ChsTransactionsMember
$ 0thr_GainonSettlementofRelatedPartyTransactions
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= thr_ChsTransactionsMember
$ 0thr_GainonSettlementofRelatedPartyTransactions
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= thr_ChsTransactionsMember