Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Tax [Abstract]
Income tax expense	$ 2,611	$ 2,624	$ 4,568	$ 4,404
Tax benefit relating to compensation expense recognized	(300)			$ (300)
Gross unrecognized tax benefits	1,000		1,000		$ 1,000
Mepco [Member]
Valuation Allowance [Line Items]
Valuation allowance against deferred tax assets attributable to Mepco	$ 1,100		$ 1,100		$ 1,100