INCOME TAXES (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
U.S. federal income tax rate
U.S. federal income tax rate (as a percent)									35.00%
Difference in income tax provision from amount computed by applying U.S. federal income tax rate to loss before income taxes
U.S. federal income tax provision (benefit) at statutory rate									$ 7,191,000	$ 1,091,000	$ 4,622,000
Research and development credit									(69,000)	(150,000)	(141,000)
Lobbying expenses									179,000	243,000	266,000
Stock based compensation expense									674,000	(32,000)	(43,000)
Other									(1,078,000)	(955,000)	(1,515,000)
State income tax expense, net of federal benefit									1,232,000	(134,000)	215,000
Change in valuation allowance									1,168,000	1,832,000	1,000,000
Total provision (benefit) for income taxes	$ 1,119,000	$ (543,000)	$ (243,000)	$ 8,964,000	$ (1,879,000)	$ (15,000)	$ 1,849,000	$ 1,940,000	9,297,000	1,895,000	4,404,000
Deferred tax assets:
Net operating loss carryforwards	36,486,000				47,793,000				36,486,000	47,793,000
Research and development tax credits	9,832,000				8,574,000				9,832,000	8,574,000
AMT and other tax credits	1,827,000				1,034,000				1,827,000	1,034,000
Intangible assets	1,678,000				751,000				1,678,000	751,000
Accrued expenses	13,548,000				12,605,000				13,548,000	12,605,000
Reserves and other	2,893,000				3,227,000				2,893,000	3,227,000
Gross deferred tax assets	66,264,000				73,984,000				66,264,000	73,984,000
Valuation allowance	(4,239,000)				(3,071,000)				(4,239,000)	(3,071,000)
Total deferred tax assets	62,025,000				70,913,000				62,025,000	70,913,000
Deferred tax liabilities:
Fixed assets	(4,351,000)				(5,320,000)				(4,351,000)	(5,320,000)
Prepaid expenses	(1,408,000)				(1,397,000)				(1,408,000)	(1,397,000)
Total deferred tax liabilities	(5,759,000)				(6,717,000)				(5,759,000)	(6,717,000)
Total deferred tax assets, net	56,266,000				64,196,000				56,266,000	64,196,000
Unrecognized tax benefits that would impact effective tax rate	5,900,000				4,800,000				5,900,000	4,800,000	4,100,000
Unrecognized tax benefits that would result in adjustments to other tax accounts	1,500,000				0				1,500,000	0	$ 0
Decrease in unrecognized tax benefits in next twelve months	1,500,000								$ 1,500,000
Assessment of deferred tax asset, term									3 years
Interest and penalties accrued on tax contingencies	345,000				$ 236,000				$ 345,000	$ 236,000
Indefinitely reinvested foreign earnings	421,000								421,000
Operating Loss Carryforwards, Deductions and Credits
Deferred tax assets:
Valuation allowance	(1,600,000)								(1,600,000)
Unrealized Capital Losses
Deferred tax assets:
Valuation allowance	(2,600,000)								(2,600,000)
Stock option deductions
Difference in income tax provision from amount computed by applying U.S. federal income tax rate to loss before income taxes
Total provision (benefit) for income taxes									9,400,000
Deferred tax liabilities:
Net operating loss carryforwards	24,500,000								24,500,000
Capital Loss Carryforward
Deferred tax liabilities:
Tax credit carryforward	394,000								394,000
Internal Revenue Service (IRS)
Deferred tax assets:
Research and development tax credits	10,700,000								10,700,000
Deferred tax liabilities:
Net operating loss carryforwards	119,100,000								119,100,000
State and local jurisdictions
Deferred tax assets:
Research and development tax credits	5,100,000								5,100,000
Deferred tax liabilities:
Net operating loss carryforwards	115,300,000								115,300,000
International operations
Deferred tax liabilities:
Indefinite operating loss carryforwards	626,000								626,000
International operations | 5 Year Carryforward
Deferred tax liabilities:
Net operating loss carryforwards	$ 834,000								$ 834,000