CASH DIVIDENDS (Details) - $ / shares			1 Months Ended		3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 28, 2016	Sep. 30, 2017	Sep. 30, 2016	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
CASH DIVIDENDS
Regular cash dividend declared per common stock			$ 1.00	$ 0.70	$ 1.00	$ 1.00	$ 1.00	$ 1.00
Regular cash dividend paid per common stock	$ 1.00	$ 0.70
Dividend record date			Oct. 20, 2017	Oct. 18, 2016
Regular quarterly cash dividend declared per common stock			$ 0.25
Special cash dividend declared per common stock				$ 0.30
Special cash dividend paid per common stock		$ 0.30