RELATED-PARTY TRANSACTIONS - Transactions with The Palisades Group (Details) - USD ($)			3 Months Ended	4 Months Ended		6 Months Ended	12 Months Ended
	Apr. 06, 2015	Jul. 01, 2013	Mar. 31, 2017	May 05, 2016	Dec. 31, 2013	Jun. 27, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Expenses from transactions with related parties	$ 263,000
COR Securities Holding, Inc. (CORSHI) | Rent Payments Reimbursement
Related Party Transaction [Line Items]
Expenses from transactions with related parties					$ 40,000
COR Securities Holding, Inc. (CORSHI) | Security Deposit
Related Party Transaction [Line Items]
Expenses from transactions with related parties					$ 34,000
COR Securities Holding, Inc. (CORSHI) | Intercompany Transaction
Related Party Transaction [Line Items]
Expenses from transactions with related parties						$ 34,000
COR Securities Holding, Inc. (CORSHI) | Leasing Costs Payments
Related Party Transaction [Line Items]
Expenses from transactions with related parties						$ 58,000
Subsidiaries | Immediate Family Member of Chief Executive Officer, Brother | Consulting Agreement
Related Party Transaction [Line Items]
Consulting agreement term		5 years
Consulting agreement minimum payment		$ 30,000
Consulting agreement payment		$ 600,000
Expenses from transactions with related parties				$ 0			$ 30,000	$ 1,200,000	$ 121,000
Written notice period for agreement termination			30 days