Condensed consolidating financial information (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
Current Assets:
Cash and cash equivalents	$ 106,609	$ 60,651	$ 28,258	$ 45,497
Restricted cash	27,761	21,412
Accounts receivable	59,501	79,008
Prepayments, supplies, and other	41,861
Other current assets	12,911
Total current assets	248,643	200,767
Property, plant, and equipment, net	1,549,626	1,388,254	284,018
Transmission system rights	178,319	180,282
Equity investments in unconsolidated affiliates	477,098	474,351
Other intangible assets, net	597,633	584,274
Goodwill	343,586	343,586
Other assets	80,805
Total assets	3,475,710	3,248,427	1,007,801
Current Liabilities:
Accounts payable and accrued liabilities	93,004
Revolving credit facility	72,800	58,000
Current portion of long-term debt	246,520	20,958
Other current liabilities	64,776
Total current liabilities	477,100	192,454
Long-term debt	1,364,685	1,404,900
Convertible debentures	193,269	189,563
Other non-current, liabilities	382,119
Equity
Preferred shares issued by a subsidiary company	221,304	221,304
Common shares	1,217,893	1,217,265
Accumulated other comprehensive income (loss)	12,216	(5,193)
Retained deficit	(395,743)	(320,622)
Total Atlantic Power Corporation shareholders' equity	1,055,670	1,112,754
Noncontrolling interest	2,867	3,027
Total equity	1,058,537	1,115,781
Total liabilities and equity	3,475,710	3,248,427
Guarantor Subsidiaries
Current Assets:
Cash and cash equivalents	100,827	58,370
Restricted cash	27,761
Accounts receivable	89,392
Prepayments, supplies, and other	39,555
Other current assets	4,055
Total current assets	261,590
Property, plant, and equipment, net	1,375,605
Transmission system rights	178,319
Equity investments in unconsolidated affiliates	5,053,320
Other intangible assets, net	582,491
Goodwill	285,358
Other assets	483,401
Total assets	8,220,084
Current Liabilities:
Accounts payable and accrued liabilities	99,992
Revolving credit facility	22,800
Current portion of long-term debt	246,520
Other current liabilities	51,308
Total current liabilities	420,620
Long-term debt	714,685
Other non-current, liabilities	1,214,271
Equity
Preferred shares issued by a subsidiary company	221,304
Common shares	5,094,502
Accumulated other comprehensive income (loss)	12,216
Retained deficit	539,619
Total Atlantic Power Corporation shareholders' equity	5,867,641
Noncontrolling interest	2,867
Total equity	5,870,508
Total liabilities and equity	8,220,084
Curtis Palmer
Current Assets:
Cash and cash equivalents	(78)	(15)
Accounts receivable	17,477
Prepayments, supplies, and other	1,167
Total current assets	18,566
Property, plant, and equipment, net	175,087
Other intangible assets, net	166,067
Goodwill	58,228
Total assets	417,948
Current Liabilities:
Accounts payable and accrued liabilities	4,704
Total current liabilities	4,704
Long-term debt	190,000
Other non-current, liabilities	8,135
Equity
Common shares	208,991
Retained deficit	6,118
Total Atlantic Power Corporation shareholders' equity	215,109
Total equity	215,109
Total liabilities and equity	417,948
Atlantic Power
Current Assets:
Cash and cash equivalents	5,860	2,296
Accounts receivable	2,996
Prepayments, supplies, and other	1,139
Other current assets	8,856
Total current assets	18,851
Equity investments in unconsolidated affiliates	865,104
Other assets	438,639
Total assets	1,322,594
Current Liabilities:
Accounts payable and accrued liabilities	38,672
Revolving credit facility	50,000
Other current liabilities	13,468
Total current liabilities	102,140
Long-term debt	460,000
Convertible debentures	193,269
Other non-current, liabilities	948
Equity
Common shares	1,217,893
Retained deficit	(651,656)
Total Atlantic Power Corporation shareholders' equity	566,237
Total equity	566,237
Total liabilities and equity	1,322,594
Eliminations
Current Assets:
Accounts receivable	(50,364)
Total current assets	(50,364)
Property, plant, and equipment, net	(1,066)
Equity investments in unconsolidated affiliates	(5,441,326)
Other intangible assets, net	(150,925)
Other assets	(841,235)
Total assets	(6,484,916)
Current Liabilities:
Accounts payable and accrued liabilities	(50,364)
Total current liabilities	(50,364)
Other non-current, liabilities	(841,235)
Equity
Common shares	(5,303,493)
Retained deficit	(289,824)
Total Atlantic Power Corporation shareholders' equity	(5,593,317)
Total equity	(5,593,317)
Total liabilities and equity	$ (6,484,916)