Restricted Cash (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Restricted Cash and Cash Equivalents Items [Line Items]
Surety, payment and performance bonds	$ 26.9	$ 20.6
Collateral payment for performance bonds	10.8	10.1
Collateral related to workers compensation policy	$ 2.3	$ 2.3

Collateral For Surety Payment And Performance Bonds

No definition available.

Name:	sbac_CollateralForSuretyPaymentAndPerformanceBonds
Namespace Prefix:	sbac_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant