Related Party Transactions - Additional Information (Detail) - Ausley McMullen, P.A [Member] $ in Millions	12 Months Ended
Dec. 31, 2013 USD ($)
Related Party Transaction [Line Items]
Legal fees	$ 1.7
Tampa Electric Company [Member]
Related Party Transaction [Line Items]
Legal fees	$ 1.7

The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_LegalFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration