Related Party Transactions (Details) (Water Star, Inc. [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Water Star, Inc. [Member]
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