Goodwill and Intangible Assets, Net (Details 2) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Changes in gross carrying amount of finite-lived intangible assets
Gross Carrying Amount	$ 66,454,000	$ 63,413,000	$ 66,454,000	$ 63,413,000	$ 69,693,000
Accumulated Amortization	(23,108,000)	(21,884,000)	(23,108,000)	(21,884,000)	(19,095,000)
Net Carrying Amount	43,346,000	41,529,000	43,346,000	41,529,000	50,598,000
Amortization expense of intangible assets	2,000,000	1,900,000	4,013,000	3,700,000
Estimated future amortization of intangible assets
Remaining six months of 2013	4,120,000		4,120,000
2014	8,064,000		8,064,000
2015	7,158,000		7,158,000
2016	6,881,000		6,881,000
2017	4,965,000		4,965,000
2018	2,886,000		2,886,000
Thereafter	9,272,000		9,272,000
Total	43,346,000		43,346,000
North America
Changes in gross carrying amount of finite-lived intangible assets
Gross Carrying Amount	39,908,000	35,581,000	39,908,000	35,581,000	37,992,000
Accumulated Amortization	(14,591,000)	(15,350,000)	(14,591,000)	(15,350,000)	(12,012,000)
Net Carrying Amount	25,317,000	20,231,000	25,317,000	20,231,000	25,980,000
Europe
Changes in gross carrying amount of finite-lived intangible assets
Gross Carrying Amount	26,546,000	27,832,000	26,546,000	27,832,000	31,701,000
Accumulated Amortization	(8,517,000)	(6,534,000)	(8,517,000)	(6,534,000)	(7,083,000)
Net Carrying Amount	18,029,000	21,298,000	18,029,000	21,298,000	24,618,000
S&P Clever
Changes in gross carrying amount of finite-lived intangible assets
Intangible assets reclassified to other non-current assets			$ 4,800,000