Commitments and contingencies (Tables)
12 Months Ended
Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]  
Schedule of Future Minimum Payments for Operating Leases
Future minimum lease payments at December 31, 2013, under operating leases with initial or remaining terms in excess of one year were as follows (dollars in thousands):
(Dollars in thousands)
 
Years ending December 31,
 
2014
$
853

2015
843

2016
850

2017
766

2018
485

Thereafter

 
$
3,797