Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012 EquityUnit Segment Venture	Dec. 31, 2011	Dec. 31, 2010 EquityUnit
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of business segments		3
Number of joint ventures		2
Period of maturity for cash and cash equivalents		Three months or less
Period of original maturity for certificate of deposits		Greater than three months
Net cash refunds of income tax payments			$ 1,500,000	$ 65,400,000
Cash payments of income taxes		1,400,000	1,300,000	1,300,000
Amortization of deferred financing costs		4,908,000	5,118,000	5,314,000
Write-off of deferred financing costs related to refinancing of credit facility			1,681,000
Write off of deferred debt issuance cost associated with senior notes	500,000			300,000
Term of management rights for income amortization		65 years
Amortization expense of deferred software costs		10,000,000	8,700,000	8,200,000
Base Management fee		2.00%
Total Base Management fee		5,100,000
Advertising costs included in continuing operations		$ 21,800,000	$ 22,200,000	$ 25,600,000
Effect of dilutive stock-based compensation awards		861,000		709,000
Potentially issuable shares under the conversion spread		3,774,000		413,000
Approximate number of common stock share which can be purchased under warrants		16,000,000
Initial strike price under warrant		27.00
Approximate number of common stock share which can be purchased under warrants		1,328,721	0	0
3.75% Convertible Notes Payable [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Interest		3.75%	3.75%
Maturity year of note		2014
Stock Options [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Stock-based compensation awards outstanding		602,000	1,401,000	1,628,000
Osceola County [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Land area covered under operating lease agreement		65.3
Grapevine [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Land area covered under operating lease agreement		10.0
Maximum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Maximum interest in non-marketable investments using cost method of accounting		20.00%
Interest in non-marketable investments using equity method of accounting		50.00%
Maximum [Member] | Software Development [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated useful life of deferred software costs		5 years
Minimum [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Interest in non-marketable investments using equity method of accounting		20.00%
Minimum [Member] | Software Development [Member]
Basis Of Presentation And Significant Accounting Policies [Line Items]
Estimated useful life of deferred software costs		3 years