Significant Accounting Policies (Details)	3 Months Ended	12 Months Ended
	Sep. 30, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Percentage of certain resort fees included in management services revenues		50.00%
Minimum future base rent on non-cancelable leases due in 2016		$ 6,800,000
Minimum future base rent on non-cancelable leases due in 2017		6,700,000
Minimum future base rent on non-cancelable leases due in 2018		6,500,000
Minimum future base rent on non-cancelable leases due in 2019		6,200,000
Minimum future base rent on non-cancelable leases due in 2020		5,900,000
Temporary unrealized losses related to debt securities		1,117,000	$ 1,487,000
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, No Previous Impairment	$ 1,300,000	$ 0	1,295,000	$ 0
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, before Tax, Including Portion Attributable to Noncontrolling Interest, Available-for-sale Securities			$ 1,500,000
Period restricted investments are to be allocated to 401(k) plan participants		6 years	7 years
Allowance for doubtful accounts		$ 0	$ 0
Capitalized indirect costs incurred		$ 200,000	600,000	$ 700,000
Timber holdings valuation sample		20.00%
Debt securities, fair value		$ 191,032,000
U.S. Treasury securities
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Temporary unrealized losses related to debt securities		79,000	0
U.S. Treasury securities		184,700,000
Corporate debt securities
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Temporary unrealized losses related to debt securities		981,000	$ 1,482,000
Debt securities, fair value		$ 6,300,000
Number of Issuers		1
Commercial paper
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Debt securities, fair value		$ 175,000,000
Number of Issuers		8
Minimum
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Estimated useful life (in years)		3 years
Minimum | Real Estate
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Estimated useful life (in years)		5 years
Maximum
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Estimated useful life (in years)		30 years
Maximum | Real Estate
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Estimated useful life (in years)		40 years