Subsequent Event (Details) (Subsequent Event [Member], USD $) In Millions, unless otherwise specified	Jan. 07, 2014
Subsequent Event [Member]
Subsequent Event [Line Items]
Purchase price	$ 160
Allowance for certain liabilities assumed	23
Net purchase price payable at closing in cash	112
Accounts receivable	$ 25

Net purchase price, remitted in cash, that is to be paid to the entity by the buyer.

No definition available.

Name:	cpwr_NetPurchasePricePayableAtClosingInCash
Namespace Prefix:	cpwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant