Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended			6 Months Ended		12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jun. 30, 2011 Water Star, Inc. [Member]	Jun. 30, 2012 Customer Lists and Service Contracts [Member]	Dec. 31, 2011 Customer Lists and Service Contracts [Member]	Jun. 30, 2012 Trade Name [Member]	Dec. 31, 2011 Trade Name [Member]	Jun. 30, 2012 Technology [Member]	Dec. 31, 2011 Technology [Member]
Goodwill Gross [Roll Forward]
Balance, beginning of period			$ 66,523
Foreign currency fluctuations			(223)
Balance, end of period	66,300		66,300
Goodwill Accumulated Impairment Losses [Roll Forward]
Balance, beginning of period			(46,220)
Foreign currency fluctuations			(250)
Balance, end of period	(46,470)		(46,470)
Goodwill Net [Roll Forward]
Balance, beginning of period			20,303
Foreign currency fluctuations			(473)
Balance, end of period	19,830		19,830
Acquired Finite-Lived Intangible Assets [Line Items]
Original cost	35,113		35,113		37,706		23,562	25,987	4,492	4,583	7,059	7,136
Accumulated amortization	(12,915)		(12,915)		(13,948)		(9,064)	(10,387)	(1,347)	(1,209)	(2,504)	(2,352)
Carrying amount	22,198		22,198		23,758		14,498	15,600	3,145	3,374	4,555	4,784
Weighted-average original life (in years)						15	15	14	14	14	13	13
Amortization expense on Intangible Assets	656	872	1,432	1,704
Estimated aggregate amortization expense of Intangible Assets [Abstract]
Remaining 2012			1,135
2013			2,285
2014			2,225
2015			2,214
2016			2,174
Thereafter			12,165
Total			22,198
Impairment loss on a customer list and technology intangible assets		$ 1,805