Commitments And Contingencies (Narrative) (Details)	1 Months Ended	3 Months Ended			12 Months Ended			114 Months Ended
	Oct. 31, 2013 USD ($)	Mar. 31, 2018 USD ($) store item	Mar. 31, 2017 USD ($)		Dec. 31, 2017 USD ($)		Dec. 31, 2015	Jun. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Payments to subsidies		$ 0	$ 0
Accrued liabilities and other		$ 76,990,000			$ 77,317,000	[1]
Number of HOAs, subsidies provided to | item		9
Period of purchase of completed VOI inventory		5 years
Inventory purchased		$ 9,673,000	$ 6,664,000	[1]
Purchase commiment remained		4,600,000
Damages per violation amount		$ 5,000
Average annual default rates		8.40%					6.90%
Percent of total delinquencies subject to letters		13.30%
Accrued liabilities		$ 1,000,000
Stock Appreciation Rights (SARs) [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Awards vesting period		5 years
Performance Units [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Period of awards right to receive cash payment		2 years
Purchase Commitment [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Total purchase commitment	$ 35,100,000
Implemented Initiative, Streamline Operations In Certain Areas, Facilitate Future Growth [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Severance expense					5,800,000
Amount of future payment		$ 700,000
Subsidies To Certain HOAs [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Accrued liabilities and other		$ 2,300,000			$ 0
Executive Officers [Member] | Stock Appreciation Rights (SARs) [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Percent of awards granted		30.00%
Executive Officers [Member] | Performance Units [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Percent of awards granted		70.00%
Senior Vice Presidents [Member] | Performance Units [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Percent of awards granted		100.00%
Executive [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Amount of future payment		$ 2,100,000							$ 2,900,000
Bass Pro [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Number of stores vacation packages are sold | store		68
Compensation paid under agreement on sales		$ 0
Percent of volume sales from agreement		12.00%	13.00%
Aggregate amount of purchaser default adjustments								$ 4,800,000

[1] * See Note 2 for summary of adjustments.