Debt - Short-Term Borrowings (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Line of Credit Facility [Line Items]
Short-term borrowings	$ 184,188	$ 66,342
Revolving Credit Facility
Line of Credit Facility [Line Items]
Short-term borrowings	184,188	$ 66,342
Minimum
Line of Credit Facility [Line Items]
Short-term borrowings	35,981		$ 31,089
Maximum
Line of Credit Facility [Line Items]
Short-term borrowings	$ 184,188		$ 111,912