Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended					3 Months Ended	12 Months Ended			3 Months Ended
	Mar. 31, 2013 City of San Francisco	Mar. 31, 2013 Litigation Related to Other Taxes	Dec. 31, 2012 Litigation Related to Other Taxes	Mar. 15, 2013 Litigation Related to Other Taxes	Jan. 11, 2013 Litigation Related to Other Taxes	Jan. 11, 2013 Litigation Related to Other Taxes Excise Tax Related Liabilities	Jan. 11, 2013 Litigation Related to Other Taxes Accrued Interest	Mar. 31, 2013 Litigation relating to occupancy tax LegalMatter	Dec. 31, 2010 Litigation relating to occupancy tax	Dec. 31, 2009 Litigation relating to occupancy tax	Dec. 31, 2012 Litigation relating to occupancy tax	Mar. 31, 2013 Matters relating to hotel booking practices
Loss Contingencies [Line Items]
Number of lawsuits filed by cities, counties and states involving hotel occupancy taxes								83
Number of lawsuits currently active								42
Number of lawsuits dismissed to date								33
Number of dismissals based on finding that defendant was not subject to local hotel occupancy tax or the local government lacked standing to pursue claims								20
Reserve for potential settlement of issues related to hotel occupancy taxes								$ 34			$ 35
Occupancy tax assessments tax payment (refund)									3	48
Tax assessments including interest and penalites	22
Litigation relating to general excise tax, court ruled amount					110	78	32
Tax penalties on assessment, percentage				50.00%
Litigation relating to general excise tax, accrual		60	110
Estimate of possible amounts in excess of accrual		$ 22
Number of Putative class action law suits												34