Summary of Segment Activity (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues from external customers	$ 18,554,494	$ 21,376,621	$ 19,214,193	$ 16,899,909	$ 15,227,457	$ 17,213,757	$ 18,151,091	$ 10,059,360	$ 76,045,217	$ 60,651,665	$ 41,084,589
Depreciation and amortization									4,197,156	3,010,787	479,456
Earnings from equity investment									49,418	24,766	59,623
Interest expense									508,123	442,849	575,199
Income (loss) from operations	(1,978,610)	$ (278,314)	$ (222,382)	$ (417,097)	(679,370)	$ 393,612	$ 546,965	$ (377,692)	(2,896,403)	(116,485)	$ (1,980,200)
Segment assets	93,053,873				99,159,591				93,053,873	99,159,591
Intangible assets	19,347,954				23,512,394				19,347,954	23,512,394
Goodwill, net	21,886,958				22,448,613				21,886,958	22,448,613
Expenditures for segment assets									1,161,475	2,938,118
Electro- Mechanical Segment
Segment Reporting Information [Line Items]
Revenues from external customers									48,674,821	42,795,060
Depreciation and amortization									940,611	864,587
Earnings from equity investment									49,418	24,766
Interest expense									231,490	113,694
Income (loss) from operations									4,457,592	3,396,452
Segment assets	44,127,035				40,445,788				44,127,035	40,445,788
Intangible assets	8,043,909				8,339,470				8,043,909	8,339,470
Goodwill, net	13,020,547				13,036,471				13,020,547	13,036,471
Expenditures for segment assets									904,701	2,003,037
Gas Segment
Segment Reporting Information [Line Items]
Revenues from external customers									27,370,396	17,856,605
Depreciation and amortization									3,497,827	2,411,112
Earnings from equity investment									0	0
Interest expense									11,450	6,293
Income (loss) from operations									(3,382,235)	(36,993)
Segment assets	35,010,182				42,127,016				35,010,182	42,127,016
Intangible assets	11,295,982				15,161,486				11,295,982	15,161,486
Goodwill, net	8,866,411				9,412,142				8,866,411	9,412,142
Expenditures for segment assets									256,774	935,081
Other Segment
Segment Reporting Information [Line Items]
Revenues from external customers									0	0
Depreciation and amortization									3,375	3,375
Earnings from equity investment									0	0
Interest expense									265,183	322,862
Income (loss) from operations									(3,971,760)	(3,475,944)
Segment assets	13,916,656				16,586,787				13,916,656	16,586,787
Intangible assets	8,063				11,438				8,063	11,438
Goodwill, net	$ 0				$ 0				0	0
Expenditures for segment assets									$ 0	$ 0