COMMITMENTS AND CONTINGENCIES (Details) - RUB / $	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Mar. 29, 2016
Exchange rate
Percentage of depreciation of functional currency against US dollar	23.00%	42.00%
Change in average percentage of the average value of the Russian Ruble against the US Dollar against corresponding prior period	37.00%	17.00%
Exchange rate (in ruble)	72.88		68.78