Income Taxes Income Taxes (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012
Current Federal Tax Expense (Benefit) [Line Items]
Expected valuation allowance reversal amount, maximum amount	$ 100

Expected federal deferred tax valuation allowance reversal amount, maximum amount

No definition available.

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