Condensed Consolidated Results of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues:
Service, rental and maintenance, net of service credits	$ 42,478	$ 50,192
Product and related sales, net	14,257	7,143
Total revenues	56,735	57,335
Operating expenses:
Cost of products sold	4,816	2,430
Service, rental and maintenance	14,303	16,465
Selling and marketing	5,653	4,924
General and administrative	13,169	15,568
Severance and restructuring	22	33
Depreciation, amortization and accretion	4,515	4,539
Total operating expenses	42,478	43,959
Operating income	14,257	13,376
Interest expense, net	(188)	(256)
Other (expense) income, net	(62)	154
Income before income tax (expense) benefit	14,007	13,274
Income tax (expense) benefit	(5,545)	27,377
Net income	$ 8,462	$ 40,651
Basic net income per common share	$ 0.38	$ 1.84
Diluted net income per common share	$ 0.37	$ 1.82
Basic weighted average common shares outstanding	22,106,543	22,063,393
Diluted weighted average common shares outstanding	22,589,483	22,333,399
Cash dividends declared per common share	$ 0.25	$ 0.25