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Redeemable Noncontrolling Interests - Additional Information (Detail) - Maximum
6 Months Ended
Jun. 30, 2015
During the first quarter of 2016  
Noncontrolling Interest [Line Items]  
Minority shareholders right to sell on remaining shares of trivago 50.00%
During the first quarter of 2018  
Noncontrolling Interest [Line Items]  
Minority shareholders right to sell on remaining shares of trivago 100.00%