Fair value measurements - Fair value on a recurring basis - Significant observable inputs (Table) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivative [Line Items]
Interest rate swaps - asset position	$ 0	$ 91
Interest rate swaps - liability position	86	0
Interest Rate Swaps
Derivative [Line Items]
Interest rate swaps - asset position	0	91
Interest rate swaps - liability position	$ 728	$ 0

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details