Income Taxes Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits Including Penalties and Interest	$ 8.9
Liability for Unrecognized Tax Benefit Expected to be Paid Within One Year	2.0
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	3.0	8.9
Unrecognized Tax Benefits, Income Tax Penalties Accrued	0.3	0.5
Decrease in Accrued Interest Resulting From Release of Liabilities for Unrecognized Tax Benefits Related to Gift Card Income Deferral as a Result of New IRS Guidance, Net	(5.9)
Various NOL Carryovers of State Taxes Expiring 2012 Through 2030 if Unused	3.4
Unrecognized Tax Benefits	8.2	12.8	11.0
Unrecognized Tax Benefits, Period Increase (Decrease)	(4.6)
Deferred Tax Assets, Valuation Allowance	2.9	9.6
Unrecognized Tax Benefits Estimated Decrease in 2012	2.8
Relates to Massachusetts Legislation Requiring Unitary Businesses to File Combined Reports [Member]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Valuation Allowance	1.2
Relates to Various State Net Operating Carryovers for DineEquity, IHOP, and Subsidiaries [Member]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 1.7