Condensed Consolidated Statements Of Stockholders' Equity (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]
Net issuance of treasury stock for vested restricted stock units, tax benefit	$ 762	$ 947

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