Derivative Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Cash flow hedges, notional amount	$ 110,000	$ 70,000
Cash flow hedges, derivative fair value, asset	0	803
Cash flow hedges, derivative fair value, liability	2,911	0
Cash flow hedges, net ineffective hedge gain/(losses)	0	0
Long-term Debt [Member]
Derivative [Line Items]
Cash flow hedges, notional amount	110,000	70,000
Cash flow hedges, derivative fair value, asset	0	803
Cash flow hedges, derivative fair value, liability	2,911	0
Cash flow hedges, net ineffective hedge gain/(losses)	$ 0	$ 0