Property and Equipment, Net (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and Equipment [Line Items]
Capitalized internal-use software, gross						$ 92,700	$ 78,100
Capitalized internal-use software, net						33,600	27,300
Depreciation and amortization, continuing operations	$ 41,747	$ 36,755	$ 33,494	$ 70,249	$ 111,996	154,452	140,926	$ 91,958
Property and Equipment [Member]
Property and Equipment [Line Items]
Depreciation and amortization, continuing operations						$ 129,400	$ 119,700	79,800
Depreciation, discontinued operations								$ 600