Project debt, movement in project debt, split between cash and non-cash items (Details) $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($)
Project debt [Abstract]
Beginning balance	$ 5,330,467
Cash flow	(248,472)
Non-cash changes	393,212
Ending balance	$ 5,475,208

The change due to current and non-current portions of project debt issued at the project level under project finance during the period - non-cash movement.

No definition available.

Name:	aby_MovementInLongTermAndShortTermProjectDebtNonCashCharges
Namespace Prefix:	aby_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration