Retirement Benefits (Schedule of estimated remaining cash contributions) (Details) $ in Thousands	Sep. 30, 2018 USD ($)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in the next fiscal year	$ 3,615
UNITED STATES | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in the next fiscal year	0
UNITED KINGDOM | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in the next fiscal year	688
JAPAN | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in the next fiscal year	224
GERMANY | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in the next fiscal year	$ 907