Subsequent Event (Details) (Subsequent Event [Member], USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2014
Subsequent Event [Member]
Subsequent Event [Line Items]
Shares repurchased (in shares)	740,000
Aggregate price of shares repurchased	$ 40.2

Treasury stock acquired value subsequent to quarter.

No definition available.

Name:	sxt_TreasuryStockAcquiredValueSubsequentToQuarter
Namespace Prefix:	sxt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration