Fair Value Measurements - Reconciliation of Recurring Financial Liability Related to Interest Rate Swaps (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of the recurring financial liability related to interest rate swaps
Derivative, Cash Received on Hedge	$ 54
Total gains/(losses) for the period:
Gain (Loss) on Foreign Currency Derivatives Recorded in Earnings, Net	36	$ 0	$ 0
Foreign currency hedges | Designated as Hedging Instrument | Cash Flow Hedge
Reconciliation of the recurring financial liability related to interest rate swaps
Beginning balance	0
Total gains/(losses) for the period:
Gain (Loss) on Foreign Currency Derivatives Recorded in Earnings, Net	(18)
Included in other comprehensive earnings	(637)
Ending balance	(601)	0
Interest Rate Swap | Designated as Hedging Instrument | Cash Flow Hedge
Reconciliation of the recurring financial liability related to interest rate swaps
Beginning balance	(768)	(1,020)
Total gains/(losses) for the period:
Included in earnings	928	(768)
Included in other comprehensive earnings	593	(516)
Ending balance		$ (768)	$ (1,020)
Derivative Asset	$ (753)