INCOME TAXES (Details 3)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Difference between the effective tax rate implicit in the consolidated financial statements and the statutory federal income tax rate
Federal income tax provision at statutory rate (as a percent)	35.00%	35.00%	35.00%
State franchise taxes, net of federal tax effect (as a percent)	6.10%	6.30%	5.00%
Tax credits, net of amortization (as a percent)	(18.30%)	(8.70%)	(16.70%)
Other, net (as a percent)	1.80%	0.90%	(0.70%)
Effective income tax rate (as a percent)	24.60%	33.50%	22.60%