Geographic Information (Details) (USD $) In Thousands, unless otherwise specified
|
3 Months Ended |
9 Months Ended |
Dec. 31, 2014
|
Dec. 31, 2013
|
Dec. 31, 2014
segment
|
Dec. 31, 2013
|
Sales by geographic area: |
|
|
|
|
Revenues |
$ 87,622us-gaap_SalesRevenueNet
|
$ 71,465us-gaap_SalesRevenueNet
|
$ 234,322us-gaap_SalesRevenueNet
|
$ 209,848us-gaap_SalesRevenueNet
|
Operating income |
|
|
|
|
Stock compensation expense |
(930)us-gaap_AllocatedShareBasedCompensationExpense
|
(663)us-gaap_AllocatedShareBasedCompensationExpense
|
(2,302)us-gaap_AllocatedShareBasedCompensationExpense
|
(1,572)us-gaap_AllocatedShareBasedCompensationExpense
|
Public company costs |
(312)thr_PublicCompanyCosts
|
(293)thr_PublicCompanyCosts
|
|
|
Operating income (loss) |
23,219us-gaap_OperatingIncomeLoss
|
17,758us-gaap_OperatingIncomeLoss
|
54,451us-gaap_OperatingIncomeLoss
|
44,266us-gaap_OperatingIncomeLoss
|
Number of Reportable Segments |
|
|
1us-gaap_NumberOfReportableSegments
|
|
United States |
|
|
|
|
Sales by geographic area: |
|
|
|
|
Revenues |
35,304us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = country_US
|
22,921us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = country_US
|
84,044us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = country_US
|
67,759us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = country_US
|
Operating income |
|
|
|
|
Operating income (loss) |
9,364us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = country_US
|
5,306us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = country_US
|
18,272us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = country_US
|
9,645us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = country_US
|
Canada |
|
|
|
|
Sales by geographic area: |
|
|
|
|
Revenues |
29,088us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = country_CA
|
23,282us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = country_CA
|
79,133us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = country_CA
|
74,450us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = country_CA
|
Operating income |
|
|
|
|
Operating income (loss) |
11,021us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = country_CA
|
8,716us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = country_CA
|
28,365us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = country_CA
|
26,616us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = country_CA
|
Europe |
|
|
|
|
Sales by geographic area: |
|
|
|
|
Revenues |
14,316us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = us-gaap_EuropeMember
|
16,824us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = us-gaap_EuropeMember
|
43,968us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = us-gaap_EuropeMember
|
44,317us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = us-gaap_EuropeMember
|
Operating income |
|
|
|
|
Operating income (loss) |
2,789us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = us-gaap_EuropeMember
|
3,453us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = us-gaap_EuropeMember
|
6,121us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = us-gaap_EuropeMember
|
7,138us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = us-gaap_EuropeMember
|
Asia |
|
|
|
|
Sales by geographic area: |
|
|
|
|
Revenues |
8,914us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = us-gaap_AsiaMember
|
8,438us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = us-gaap_AsiaMember
|
27,177us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = us-gaap_AsiaMember
|
23,322us-gaap_SalesRevenueNet / us-gaap_StatementGeographicalAxis = us-gaap_AsiaMember
|
Operating income |
|
|
|
|
Operating income (loss) |
1,287us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = us-gaap_AsiaMember
|
1,239us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = us-gaap_AsiaMember
|
5,020us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = us-gaap_AsiaMember
|
3,381us-gaap_OperatingIncomeLoss / us-gaap_StatementGeographicalAxis = us-gaap_AsiaMember
|
Unallocated |
|
|
|
|
Operating income |
|
|
|
|
Stock compensation expense |
(930)us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_StatementGeographicalAxis = us-gaap_MaterialReconcilingItemsMember
|
(663)us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_StatementGeographicalAxis = us-gaap_MaterialReconcilingItemsMember
|
(2,302)us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_StatementGeographicalAxis = us-gaap_MaterialReconcilingItemsMember
|
(1,572)us-gaap_AllocatedShareBasedCompensationExpense / us-gaap_StatementGeographicalAxis = us-gaap_MaterialReconcilingItemsMember
|
Public company costs |
|
|
$ (1,025)thr_PublicCompanyCosts / us-gaap_StatementGeographicalAxis = us-gaap_MaterialReconcilingItemsMember
|
$ (942)thr_PublicCompanyCosts / us-gaap_StatementGeographicalAxis = us-gaap_MaterialReconcilingItemsMember
|