INVESTMENT IN NUSTAR ENERGY Narrative 1 (Details) - NuStar Energy Preferred Unit Offering 2016 [Member] $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2016 $ / shares
Subsidiary, Sale of Stock [Line Items]
Preferred units issued by NuStar Energy | shares	9,060,000
Distribution percentage of NuStar Energy's preferred units	8.50%
Price of preferred units issued by NuStar Energy, per unit	$ 25.00	$ 25.00
Proceeds received by NuStar Energy, net of issuance cost, from issuance of NuStar Energy preferred units | $	$ 218.4
Liquidation preference of NuStar Energy's preferred units	$ 25.00	$ 25.00
Minimum per unit quarterly distribution of NuStar Energy's preferred units, annualized	$ 2.125
Description of floating dividend rate of NuStar Energy's preferred units		three-month LIBOR plus a spread of 6.766%