DEBT, CREDIT FACILITIES, AND CAPITAL LEASE OBLIGATIONS (Interest Rates on TEP's Variable Rate IDBs) (Detail) (TUCSON ELECTRIC POWER COMPANY, Variable Rate Demand Obligation [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
TUCSON ELECTRIC POWER COMPANY | Variable Rate Demand Obligation [Member]
Schedule of Interest Rate [Line Items]
Average Interest Rate	0.10%	0.17%	0.18%
Range of Average weekly interest rate, minimum	0.06%	0.06%	0.05%
Average Weekly Interest Rate Range Maximum	0.25%	0.26%	0.34%