Condensed consolidating financial information (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net cash provided by operating activities	$ 66,492	$ 20,347
Cash flows used in investing activities:
Change in restricted cash	(6,349)	(7,524)
Biomass development costs	(123)	(308)
Purchase of property, plant and equipment	(164,126)
Net cash used in investing activities	(170,615)	(18,115)
Cash flows provided by financing activities:
Repayment of project-level debt	(2,725)	(3,400)
Deferred financing costs	(10,179)
Proceeds from project level debt	184,216	2,781
Repayments of revolving credit facility borrowings	(8,000)
Proceeds from revolving credit facility borrowings	22,800
Dividends paid	(36,031)	(18,852)
Net cash provided by (used in) financing activities	150,081	(19,471)
Net (decrease) increase in cash and cash equivalents	45,958	(17,239)
Cash and cash equivalents at beginning of period	60,651	45,497
Cash and cash equivalents at end of period	106,609	28,258
Guarantor Subsidiaries
Cash flows from operating activities:
Net cash provided by operating activities	30,019
Cash flows used in investing activities:
Cash paid for acqusitions, net of cash acquired	198
Change in restricted cash	(6,349)
Biomass development costs	(123)
Purchase of property, plant and equipment	(164,126)
Net cash used in investing activities	(170,400)
Cash flows provided by financing activities:
Repayment of project-level debt	(2,725)
Deferred financing costs	(10,179)
Proceeds from project level debt	184,216
Repayments of revolving credit facility borrowings	(8,000)
Proceeds from revolving credit facility borrowings	22,800
Dividends paid	(3,274)
Net cash provided by (used in) financing activities	182,838
Net (decrease) increase in cash and cash equivalents	42,457
Cash and cash equivalents at beginning of period	58,370
Cash and cash equivalents at end of period	100,827
Curtis Palmer
Cash flows from operating activities:
Net cash provided by operating activities	(46)
Cash flows used in investing activities:
Purchase of property, plant and equipment	(17)
Net cash used in investing activities	(17)
Cash flows provided by financing activities:
Net (decrease) increase in cash and cash equivalents	(63)
Cash and cash equivalents at beginning of period	(15)
Cash and cash equivalents at end of period	(78)
Atlantic Power
Cash flows from operating activities:
Net cash provided by operating activities	36,519
Cash flows used in investing activities:
Cash paid for acqusitions, net of cash acquired	(198)
Net cash used in investing activities	(198)
Cash flows provided by financing activities:
Dividends paid	(32,757)
Net cash provided by (used in) financing activities	(32,757)
Net (decrease) increase in cash and cash equivalents	3,564
Cash and cash equivalents at beginning of period	2,296
Cash and cash equivalents at end of period	$ 5,860