Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Goodwill, Gross
Balance, beginning of period	$ 66,523	$ 67,008
Additions		688
Foreign currency fluctuations	2,062	(1,173)
Balance, end of period	68,585	66,523	67,008
Accumulated Impairment Losses
Balance, beginning of period	(46,220)	(46,585)
Additions		0
Foreign currency fluctuations	(2,648)	365
Balance, end of period	(48,868)	(46,220)	(46,585)
Goodwill, Net
Balance, beginning of period	20,303	20,423
Additions		688
Foreign currency fluctuations	(586)	(808)
Balance, end of period	19,717	20,303	20,423
Original cost	35,671	37,706
Accumulated amortization	(14,278)	(13,948)
Intangible Assets, Net	21,393	23,758
Impairment of Intangible Assets		1,805
Amortization expense	2,800	3,330	3,166
Estimated aggregate amortization expense of Intangible Assets
2013	2,213
2014	2,178
2015	2,154
2016	2,141
2017	1,877
Thereafter	10,830
Total	21,393
Water Star, Inc.
Goodwill, Net
Weighted-average original life (in years)	15 years
Customer Lists and Service Contracts
Goodwill, Net
Original cost	23,817	25,987
Accumulated amortization	(9,907)	(10,387)
Intangible Assets, Net	13,910	15,600
Weighted-average original life (in years)	15 years	14 years
Trade Name
Goodwill, Net
Original cost	4,657	4,583
Accumulated amortization	(1,565)	(1,209)
Intangible Assets, Net	3,092	3,374
Weighted-average original life (in years)	14 years	14 years
Technology
Goodwill, Net
Original cost	7,197	7,136
Accumulated amortization	(2,806)	(2,352)
Intangible Assets, Net	$ 4,391	$ 4,784
Weighted-average original life (in years)	13 years	13 years