Condensed Consolidated Statements of Equity (Parenthetical)	3 Months Ended
Mar. 31, 2019 shares
Statement of Stockholders' Equity [Abstract]
Shares repurchased but not yet settled (in shares)	33,263

Stock Repurchased During Period, Not Settled, Shares

No definition available.

Name:	gpk_StockRepurchasedDuringPeriodNotSettledShares
Namespace Prefix:	gpk_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration