Goodwill and Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill not expected to be deductible for tax purposes	$ 405.7

Total amount of goodwill not expected to be deductible for tax purposes.

No definition available.

Name:	cci_GoodwillNotExpectedToBeDeductibleForTaxPurposes
Namespace Prefix:	cci_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant