ACQUISITIONS, GOODWILL, AND ACQUIRED INTANGIBLE ASSETS Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	9 Months Ended			12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Purchase Price
Cash paid, net of cash acquired	$ 0	$ (1,220)		$ (28)	$ (1,192)
Allocation
Goodwill	14,698			14,698		$ 14,698
Less: accumulated amortization of acquired intangible assets	(9,283)			(9,283)		(6,443)
Total intangible assets, net	8,288			8,288		$ 10,913
Cirrus Technologies, SpeedRoute, And Pro Securities [Member]
Purchase Price
Cash paid, net of cash acquired			$ 9,353
Common stock issued			18,149
Purchase Price			27,502
Allocation
Goodwill			11,914
Intangibles	16,000		16,000	16,000
Accounts receivable and other assets			2,565
Other liabilities assumed			(2,977)
Assets acquired and liabilities assumed, net			$ 27,502
Less: accumulated amortization of acquired intangible assets	(8,160)			(8,160)
Total intangible assets, net	7,840			7,840
Cirrus Technologies, SpeedRoute, And Pro Securities [Member] | Other
Allocation
Indefinite-lived intangible assets acquired	200			200
Cirrus Technologies, SpeedRoute, And Pro Securities [Member] | Technology and developed software
Allocation
Finite-lived intangible assets acquired	$ 13,600			13,600
Useful Life	3 years 3 months 23 days
Cirrus Technologies, SpeedRoute, And Pro Securities [Member] | Customer relationships
Allocation
Finite-lived intangible assets acquired	$ 1,900			1,900
Useful Life			0 years
Cirrus Technologies, SpeedRoute, And Pro Securities [Member] | Trade names
Allocation
Finite-lived intangible assets acquired	$ 300			$ 300
Useful Life	6 years 4 months 20 days