INCOME TAXES - Statutory Federal Income Tax Rate and Effective Income Tax Rate Reconciliation (Details)	3 Months Ended		12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Statutory federal income tax rate			35.00%	35.00%	35.00%
Domestic production activities deductions			(2.60%)	(8.70%)	(0.00%)
Federal and state tax credits			(2.00%)	(2.00%)	(1.20%)
Excess tax benefits from restricted stock vestings			(0.70%)	(0.00%)	(0.00%)
State income taxes			1.80%	1.40%	2.10%
Uncertain tax positions			1.60%	3.30%	0.90%
Nondeductible expenses			0.70%	0.60%	1.00%
Other			0.30%	(1.30%)	(0.20%)
Effective federal and state income tax rate	19.00%	20.00%	34.10%	28.30%	37.60%