Income Taxes - Deferred Tax Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Components of Deferred Tax Assets and Liabilities [Abstract]
Workers’ compensation insurance reserve	$ 2.7	$ 2.6
Allowance for doubtful accounts	3.1	3.0
Legal and merger costs	3.6	2.7
Other	7.7	7.5
Less valuation allowance	(16.4)	(15.1)
Total deferred tax assets—current	0.7	0.7
Prepaid expenses	(3.9)	(3.2)
Total deferred tax liabilities—current	(3.9)	(3.2)
Net current deferred tax liabilities	(3.2)	(2.5)
Federal tax credit carry-forwards	28.9	28.3
Federal net operating loss carry-forwards	91.4	77.3
State net operating loss carry-forwards	9.8	11.7
Capital loss carry-forward	6.3	6.4
Deferred compensation	2.6	2.9
Pre-opening expenses capitalized for tax purposes	11.6	10.9
ACDL Investment Write-down	9.1	0
Share-based compensation expense—book cost	11.9	12.1
Land, building, vessels and equipment, net	0	31.6
Other	18.6	10.8
Less valuation allowance	(184.7)	(190.3)
Total deferred tax assets—non-current	5.5	1.7
Deferred Tax Liabilities, Property, Plant and Equipment	(2.9)	0
Intangible assets	(6.1)	(5.1)
Total deferred tax liabilities—non-current	(9.0)	(5.1)
Net non-current deferred tax liabilities	(3.5)	(3.4)
Total deferred tax assets	207.3	207.7
Less valuation allowances	(201.1)	(205.4)
Less total deferred tax liabilities	(12.9)	(8.2)
Net deferred tax liabilities	$ (6.7)	$ (5.9)