Related Party Transactions (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012
Business Acquisition [Line Items]
Amount of total installment payments	$ 1,500

The amount of total installment payments to be made by acquiring company as part of business acquisition.

No definition available.

Name:	tnc_AmountOfTotalInstallmentPayments
Namespace Prefix:	tnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant