Related party transactions (Details) (USD $)	0 Months Ended		12 Months Ended					0 Months Ended	12 Months Ended			0 Months Ended
	Oct. 25, 2011	Sep. 14, 2011	Dec. 31, 2012	Dec. 31, 2011	Jul. 19, 2012	Dec. 31, 2010	Mar. 25, 2013 Chief Executive Officer [Member]	May 25, 2010 Chief Executive Officer [Member] Stock Option [Member]	Dec. 31, 2012 AJLR Partnership [Member]	Dec. 31, 2012 Estate Gold [Member]	Dec. 31, 2012 Related Party Compensation [Member]	May 25, 2010 NTR [Member]	May 25, 2010 NTR [Member] Stock Option [Member]
Related Party Transaction [Line Items]
Sales to major customer, percent of revenues			43.00%	41.00%
Payments to supplier, percent of purchases			22.00%	23.00%
Due to NTR			$ 1,278,000
Credit facility amount, maximum					7,500,000
Outstanding balance of credit facility			3,583,358
Interest rate, credit					2.00%
Acquired ownership percentage of SBT		100.00%
Consideration paid for acquisition of shares												3,600,000
Shares issued in SBT business acquisition		600,000
Weighted average exercise price	$ 15.0		$ 14.21	$ 13.76		$ 2.01							$ 6.0
Options granted	5,000,000			5,000,000				1,628,014				3,000,000	1,000,000
Expiration date of options	Oct. 25, 2016
Payables forgiven	2,500,000	2,000,000
Shares issued upon debt forgiveness	5,000,000	400,000
Loss on settlement of debt with related party		(1,720,000)
Common stock, shares outstanding			12,175,584	12,163,943			1,520,812
Purchases from related party									2,084,727	96,116
Proceeds from related party										183,650
Related party revenue									415,527	274,624
Related party transaction amount											176,733
Stock based compensation				2,640,713
Fair value of NTR Options	$ 5,140,713