Acquisition of Businesses - Schedule of Recognized Assets Acquired and Liabilities Assumed (Details) $ in Thousands, € in Millions, £ in Millions						9 Months Ended
	Nov. 24, 2014 EUR (€)	Nov. 24, 2014 USD ($)	Oct. 07, 2014 USD ($)	Sep. 16, 2014 GBP (£)	Sep. 16, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Purchase price, net of cash acquired						$ 430	$ 40,775
Excess purchase price over fair value of net assets acquired (“goodwill”)						$ 186,319		$ 194,197
Blitz Communication Group Limited
Business Acquisition [Line Items]
Purchase price				£ 15.0	$ 24,416
Cash acquired					(190)
Purchase price, net of cash acquired					24,226
Accounts receivable, net					264
Inventory					433
Prepaid expenses					410
Property and equipment					5,951
Intangible assets					8,692
Total assets acquired					15,750
Accounts payable					1,232
Accrued liabilities					2,246
Customer deposits					199
Deferred tax liability					468
Revolving credit facility					488
Accrued dilapidations					417
Total liabilities acquired					5,050
Total fair value of net assets acquired					10,700
Excess purchase price over fair value of net assets acquired (“goodwill”)					$ 13,526
onPeak LLC
Business Acquisition [Line Items]
Purchase price			$ 42,950
Cash acquired			(4,064)
Purchase price, net of cash acquired			38,886
Accounts receivable, net			4,008
Prepaid expenses			640
Property and equipment			2,450
Other non-current assets			309
Intangible assets			14,100
Total assets acquired			21,507
Accounts payable			738
Accrued liabilities			3,341
Customer deposits			4,225
Deferred tax liability			1,576
Other liabilities			309
Total liabilities acquired			10,189
Total fair value of net assets acquired			11,318
Excess purchase price over fair value of net assets acquired (“goodwill”)			27,568
Travel Planners, Inc
Business Acquisition [Line Items]
Purchase price			33,674
Additional purchase price paid for tax election			896
Cash acquired			(4,204)
Working capital adjustment			(279)
Purchase price, net of cash acquired			30,087
Accounts receivable, net			1,450
Prepaid expenses			120
Property and equipment			93
Intangible assets			14,400
Total assets acquired			16,063
Accounts payable			488
Accrued liabilities			1,557
Customer deposits			4,525
Total liabilities acquired			6,570
Total fair value of net assets acquired			9,493
Excess purchase price over fair value of net assets acquired (“goodwill”)			$ 20,594
N200 Limited and Affiliates
Business Acquisition [Line Items]
Purchase price	€ 9.7	$ 12,068
Cash acquired		(943)
Working capital adjustment		458
Contingent consideration		1,145
Purchase price, net of cash acquired		12,728
Accounts receivable, net		1,732
Inventory		46
Prepaid expenses		115
Property and equipment		1,280
Intangible assets		3,682
Total assets acquired		6,855
Accounts payable		421
Accrued liabilities		1,057
Customer deposits		569
Deferred tax liability		911
Other liabilities		106
Total liabilities acquired		3,064
Total fair value of net assets acquired		3,791
Excess purchase price over fair value of net assets acquired (“goodwill”)		$ 8,937