Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Stock option exercises, tax benefit	$ 0	$ 0	$ 580
Net issuance of treasury stock for vested restricted stock units, tax benefit	$ 3,256	$ 460	$ 721

Reductions in the entity's income taxes that arise when compensation cost (from non-qualified restricted stock units) recognized on the entity's tax return exceeds compensation cost from non-qualified restricted stock units recognized on the income statement. This element represents the tax benefit related to the treasury stocks that were reissued for the restricted stock units.

No definition available.

Name:	slgn_TaxBenefitFromIssuanceOfTreasuryStockForVestedRestrictedUnits
Namespace Prefix:	slgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration