Intangible Asset and Goodwill (Details 3) (USD $)	3 Months Ended					3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended			3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 Existing technology	Dec. 31, 2013 Existing technology	Mar. 31, 2014 Existing technology Minimum	Dec. 31, 2013 Existing technology Minimum	Mar. 31, 2014 Existing technology Maximum	Dec. 31, 2013 Existing technology Maximum	Mar. 31, 2014 Customer contracts and contractual relationships	Dec. 31, 2013 Customer contracts and contractual relationships	Mar. 31, 2014 Customer contracts and contractual relationships Minimum	Dec. 31, 2013 Customer contracts and contractual relationships Minimum	Mar. 31, 2014 Customer contracts and contractual relationships Maximum	Dec. 31, 2013 Customer contracts and contractual relationships Maximum	Mar. 31, 2014 Non-compete agreements	Dec. 31, 2013 Non-compete agreements	Mar. 31, 2014 Favorable contracts	Mar. 31, 2013 Favorable contracts	Dec. 31, 2013 Favorable contracts
Components of intangible assets
Useful Life (in years)						3 years	3 years	10 years	10 years			1 year	1 year	10 years	10 years	3 years	3 years
Gross Carrying Amount	$ 216,714,000		$ 217,595,000	$ 185,321,000	$ 186,202,000					$ 31,093,000	$ 31,093,000					$ 300,000	$ 300,000
Accumulated Amortization	(107,454,000)		(100,423,000)	(86,476,000)	(80,961,000)					(20,695,000)	(19,204,000)					(283,000)	(258,000)
Net Carrying Amount	109,260,000		117,172,000	98,845,000	105,241,000					10,398,000	11,889,000					17,000	42,000	100,000		1,000,000
Cash received related to favorable contracts																		900,000	1,400,000
Amortization expense for intangible assets	$ 6,797,000	$ 7,040,000