Consolidated Statement Of Changes In Shareholders' Equity (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock At Cost [Member]	Accumulated Other Comprehensive Income [Member]	Total
Beginning Balance at Dec. 31, 2011	$ 666	$ 165,712	$ 947,156	$ (813,684)	$ 727	$ 300,577
Beginning Balance, shares at Dec. 31, 2011	66,602,486			19,882,289
Net income			26,847			26,847
Dividends paid ($0.055 per share)			(2,574)			(2,574)
Exercises of stock options and vesting of non-vested stock, including excess tax effect	2	1,592		(7)		1,587
Exercises of stock options and vesting of non-vested stock, including excess tax effect (shares)	230,747			142
Stock-based compensation		1,525				1,525
Foreign currency translation					204	204
Unrealized gain on available-for-sale investments, net of income taxes					182	182
Ending Balance at Mar. 31, 2012	$ 668	$ 168,829	$ 971,429	$ (813,691)	$ 1,113	$ 328,348
Ending Balance, shares at Mar. 31, 2012	66,833,233			19,882,431