Financial Statement Schedule I (Details 4) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements
Net revenues	$ 2,960,626,610us-gaap_SalesRevenueNet	$ 1,654,356,064us-gaap_SalesRevenueNet	$ 1,294,829,413us-gaap_SalesRevenueNet
Cost of revenues	2,379,633,234us-gaap_CostOfGoodsAndServicesSold	1,378,661,093us-gaap_CostOfGoodsAndServicesSold	1,204,467,983us-gaap_CostOfGoodsAndServicesSold
Gross profit	580,993,376us-gaap_GrossProfit	275,694,971us-gaap_GrossProfit	90,361,430us-gaap_GrossProfit
Operating expenses:
Selling expenses	125,796,632us-gaap_SellingExpense	88,426,136us-gaap_SellingExpense	91,052,729us-gaap_SellingExpense
General and administrative expenses	76,826,038us-gaap_GeneralAndAdministrativeExpense	44,767,586us-gaap_GeneralAndAdministrativeExpense	128,826,340us-gaap_GeneralAndAdministrativeExpense
Research and development expenses	12,056,951us-gaap_ResearchAndDevelopmentExpense	11,684,993us-gaap_ResearchAndDevelopmentExpense	12,998,122us-gaap_ResearchAndDevelopmentExpense
Total operating expenses	214,679,621us-gaap_OperatingExpenses	144,878,715us-gaap_OperatingExpenses	232,877,191us-gaap_OperatingExpenses
Income (loss) from operations	366,313,755us-gaap_OperatingIncomeLoss	130,816,256us-gaap_OperatingIncomeLoss	(142,515,761)us-gaap_OperatingIncomeLoss
Other income (expenses):
Interest expense	(48,905,848)us-gaap_InterestExpense	(46,244,456)us-gaap_InterestExpense	(53,304,640)us-gaap_InterestExpense
Interest income	14,361,107us-gaap_InvestmentIncomeInterest	11,972,758us-gaap_InvestmentIncomeInterest	13,359,962us-gaap_InvestmentIncomeInterest
Foreign exchange loss	32,218,686	51,468,616	10,707,889
Others	1,623,087us-gaap_OtherNonoperatingIncomeExpense	427,560us-gaap_OtherNonoperatingIncomeExpense
Other income (expenses), net:	(45,484,104)us-gaap_NonoperatingIncomeExpense	(74,548,528)us-gaap_NonoperatingIncomeExpense	(56,103,440)us-gaap_NonoperatingIncomeExpense
Income (loss) before income taxes and equity in loss of unconsolidated investees	320,829,651	56,267,728	(198,619,201)
Income tax expense	(77,430,913)us-gaap_IncomeTaxExpenseBenefit	(7,638,786)us-gaap_IncomeTaxExpenseBenefit	5,433,410us-gaap_IncomeTaxExpenseBenefit
Equity in loss (earnings) of unconsolidated investees	(487,346)	3,064,006	1,969,306
Net income (loss) attributable to Canadian Solar Inc.	239,501,317	31,659,276	(195,468,691)
Parent Company
Condensed Financial Statements
Net revenues	15,899,641	11,802,218	111,414,327
Cost of revenues	4,401,056	5,282,597	80,190,744
Gross profit	11,498,585	6,519,621	31,223,583
Operating expenses:
Selling expenses	3,999,535	3,520,618	3,649,131
General and administrative expenses	8,331,139	5,724,288	11,955,578
Research and development expenses	415,857	714,980	764,145
Total operating expenses	12,746,531	9,959,886	16,368,854
Income (loss) from operations	(1,247,946)	(3,440,265)	14,854,729
Other income (expenses):
Interest expense	(6,328,588)		(255,502)
Interest income	10,369,290	12,021,534	1,559,207
Foreign exchange loss	5,335,145	8,454,989	622,816
Others	47,092	427,560
Other income (expenses), net:	(1,247,351)	3,994,105	680,889
Income (loss) before income taxes and equity in loss of unconsolidated investees	(2,495,297)	553,840	15,535,618
Income tax expense	(1,006,201)	(1,275,114)	(7,441,590)
Equity in earnings (loss) of subsidiaries	243,283,097	35,132,523	(202,699,044)
Equity in loss (earnings) of unconsolidated investees	280,282	2,751,973	863,675
Net income (loss) attributable to Canadian Solar Inc.	$ 239,501,317	$ 31,659,276	$ (195,468,691)

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