Project debt, Details of project debt (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Project debt [Abstract]
Non-current	$ 4,908,678	$ 5,228,917
Current	305,997	246,291
Total Project debt	$ 5,214,675	$ 5,475,208

The non-current portion of non-current project debt issued at the project level under project finance.

No definition available.

Name:	aby_NoncurrentPortionOfNoncurrentProjectDebt
Namespace Prefix:	aby_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant