Restructuring Charges (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($)
Restructuring Charges
Balance at the beginning of the period	$ 2,224
Balance at the end of the period	1,714
Restructuring Plan 2011 | Consolidation of leased facilities
Restructuring Charges
Balance at the beginning of the period	833
Utilized - cash	(301)
Balance at the end of the period	532
Restructuring Plan 2010 | Consolidation of leased facilities
Restructuring Charges
Balance at the beginning of the period	1,391
Utilized - cash	(209)
Balance at the end of the period	$ 1,182