Segment Information (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reconciliation of total operating income to the consolidated statement of income
Operating income	$ 5,260	$ 7,892	$ 11,181	$ 16,030
Income before income tax provision	1,098	3,788	2,689	7,745
Operating segment
Reconciliation of total operating income to the consolidated statement of income
Operating income	5,260	7,892	11,181	16,030
Corporate other expense	(4,162)	(4,104)	(8,492)	(8,285)
Income before income tax provision	$ 1,098	$ 3,788	$ 2,689	$ 7,745