Ameresco, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Business Segment Information (Details)

Business Segment Information (Details) (USD $)	3 Months Ended												12 Months Ended
Business Segment Information (Details) (USD $)	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012 segment	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Number of reportable segments													4
Unallocated corporate expenses													$ 44,399,958	$ 39,477,839	$ 30,721,689
Income before taxes and unallocated corporate expenses													18,088,251	9,712,686	8,662,872
Total revenue	156,591	163,906	164,100	146,573	188,494	227,804	165,482	146,420	179,342	191,901	141,355	105,629	631,170,565	728,200,318	618,226,659
Interest income													138,362	76,272	431,000
Interest expense													3,634,146	4,206,622	4,944,769
Depreciation and amortization of intangible assets													19,340,090	14,008,738	11,419,186
Income (loss) before taxes	6,048	9,396	6,846	2,317	10,868	13,713	11,927	7,672	12,688	16,162	9,643	1,207	24,606,886	44,180,105	39,699,301
Total assets	675,472,003				645,597,467				582,450,973				675,472,003	645,597,467	582,450,973
Capital expenditures													52,251,348	45,212,139	39,626,528
U.S Federal
Segment Reporting Information [Line Items]
Number of U.S. regions reported in aggregate													4
Total revenue													73,469,139	145,198,722	177,522,351
Interest income													0	0	0
Interest expense													0	0	0
Depreciation and amortization of intangible assets													318,140	225,620	181,174
Income (loss) before taxes													2,263,079	19,251,538	21,443,966
Total assets	121,618,149				150,408,837				210,456,641				121,618,149	150,408,837	210,456,641
Capital expenditures													1,127,879	215,021	672,617
Central U.S Region
Segment Reporting Information [Line Items]
Total revenue													87,804,977	86,376,323	100,327,256
Interest income													0	0	0
Interest expense													0	0	0
Depreciation and amortization of intangible assets													19,779	18,665	8,733
Income (loss) before taxes													9,355,435	5,643,073	10,378,682
Total assets	21,260,074				15,035,157				26,338,559				21,260,074	15,035,157	26,338,559
Capital expenditures													0	17,939	68,097
Other U.S Regions
Segment Reporting Information [Line Items]
Total revenue													262,235,481	268,211,318	142,456,529
Interest income													0	0	0
Interest expense													0	0	0
Depreciation and amortization of intangible assets													0	0	0
Income (loss) before taxes													43,478,778	47,074,233	25,582,985
Total assets	285,304,044				273,751,371				122,524,864				285,304,044	273,751,371	122,524,864
Capital expenditures													3,366,237	3,202,706	1,606,508
Canada
Segment Reporting Information [Line Items]
Total revenue													60,563,724	106,530,807	101,408,237
Interest income													0	5,615	33,195
Interest expense													719,155	118,315	2,686
Depreciation and amortization of intangible assets													579,242	835,739	492,174
Income (loss) before taxes													(4,178,699)	1,976,414	4,352,485
Total assets	59,467,354				68,321,537				72,012,318				59,467,354	68,321,537	72,012,318
Capital expenditures													4,246,322	3,776,141	10,277,279
All Other
Segment Reporting Information [Line Items]
Total revenue													147,097,244	121,883,148	96,512,286
Interest income													138,362	70,657	397,805
Interest expense													2,914,991	4,088,307	4,942,083
Depreciation and amortization of intangible assets													18,422,929	12,928,714	10,737,105
Income (loss) before taxes													(26,311,707)	(29,765,153)	(22,058,817)
Total assets	187,822,382				138,080,565				151,118,591				187,822,382	138,080,565	151,118,591
Capital expenditures													$ 43,510,910	$ 38,000,332	$ 27,002,027