Commitments and contingencies (Details Textual)	1 Months Ended	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) gal	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jun. 29, 2011 gal
Commitments And Contingencies [Line Items]
Operating Leases, Rent Expense, Net					$ 834,738	$ 821,845	$ 812,658
Royalty Payment Percentage					7.50%
Employment Agreement Base Annual Salaries					$ 2,100,000
Cayman Water Retail Operations, Percentage Of Gross Profit					56.00%	56.00%	54.00%
Cayman Water Retail Operations, Percentage Of Revenue					40.00%	40.00%	36.00%
Noncancellable Lease Term Expiration Date					2035
Long-term Purchase Commitment, Amount					$ 2,900,000
Operating Income (Loss)					$ 1,823,302	$ 8,468,064	$ 6,461,059
Long-term Purchase Commitment, Date					Dec. 31, 2019
Foreign Currency Transaction Gain (Loss), before Tax					$ 50,299	(485,291)	(111,409)
Cash and Cash Equivalents, at Carrying Value, Total					39,254,116	44,792,734	35,713,689	$ 33,626,516
Accounts Receivable, Net, Current, Total					16,500,798	9,529,016
Impairment of Long-Lived Assets Held-for-use					2,000,000	0	0
Indonesia, Rupiahs
Commitments And Contingencies [Line Items]
Cash and Cash Equivalents, at Carrying Value, Total					28,000
Accounts Receivable, Net, Current, Total					$ 7,000
Cw Bahamas [Member]
Commitments And Contingencies [Line Items]
Delivery Terms Volume Of Water Per Week | gal					63,000,000
Cw Belize [Member]
Commitments And Contingencies [Line Items]
Delivery Terms, Volume of water per day | gal									450,000
CW Bali [Member]
Commitments And Contingencies [Line Items]
Plant Capacity | gal					790,000
Operating Income (Loss)					$ (2,744,361)	(483,544)	(458,393)
Foreign Currency Transaction Gain (Loss), before Tax	$ (542,000)	$ 28,000	$ (309,000)	$ 202,000
Translation Adjustment Functional to Reporting Currency, Net of Tax		(549,555)		(549,555)	549,555
Impairment of Long-Lived Assets Held-for-use		2,000,000			2,000,000	0	$ 0
Net Assets					1,200,000
CW Bali [Member] | Indonesia, Rupiahs
Commitments And Contingencies [Line Items]
Translation Adjustment Functional to Reporting Currency, Net of Tax		$ (549,555)		$ (549,555)	$ (549,555)	$ (533,365)