CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 38,525,000	$ 36,368,000
Finite-Lived Intangible Assets, Accumulated Amortization	96,461,000	91,312,000
Other Finite-Lived Intangible Assets, Accumulated Amortization	$ 2,342,000	$ 2,000,000
SHAREHOLDERS' EQUITY:
Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, shares authorized ( in shares)	5,000,000	5,000,000
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized (in shares)	100,000,000	100,000,000
Common Stock, shares issued (in shares)	48,574,065	48,476,034
Common Stock, shares outstanding (in shares)	47,212,428	47,118,171
Treasury Stock
Treasury stock, shares	1,361,637	1,357,863
Series A Nonconvertible Preferred Stock [Member]
Shareholders' Equity A Nonconvertible Preferred Stock
Preferred Stock, shares issued (in shares)	200,000	200,000
Preferred Stock, shares outstanding (in shares)	200,000	200,000
Preferred Stock, liquidation value per share (in dollars per share)	$ 7.50	$ 7.50
Preferred Stock, liquidation value	$ 1,500,000	$ 1,500,000