Defined Benefit Plans (Schedule of Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Service cost	$ 2,113	$ 2,380	$ 6,211	$ 7,241
Interest cost	56	179	172	551
Expected return on plan assets	(167)	(248)	(496)	(756)
Employee contributions	(448)	(442)	(1,203)	(1,342)
Amortization	117	313	346	939
Defined Benefit Plan, Other Costs	0	(821)	0	(821)
Total net periodic benefit cost	$ 1,671	$ 1,361	$ 5,030	$ 5,812