Fair Value Measurements (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	$ 1,753	$ 1,142
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	18,641	28,852	17,638	27,710
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	$ (750)