Retirement Benefits (Schedule of Allocation of Plan Assets, Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Pension Plans, Defined Benefit [Member]
Fair value of plan assets	$ 208,812	$ 196,253	$ 205,161
United States Pension Plans of US Entity, Defined Benefit [Member]
Fair value of plan assets	145,886	135,590	142,090
Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	62,926	60,663	63,071
United Kingdom Plan, Defined Benefit [Member]
Fair value of plan assets	50,914
Japan Plan, Defined Benefit [Member]
Fair value of plan assets	12,012
Other Postretirement Benefit Plans, Defined Benefit [Member]
Fair value of plan assets	0	0	$ 0
Cash and Cash Equivalents [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	6,904	668
Pooled funds: Index linked U.K. government securities fund [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	5,009	4,716
Pooled funds: Index linked U.K. long-term government securities fund [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	11,998	10,583
Mutual funds: U.S. corporate bond fund [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	56,813	56,210
Pooled funds: Index linked U.K. corporate bonds fund [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	16,180	16,613
Pooled funds: Japanese fixed income securities [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	5,321	4,805
Pooled funds: International fixed income securities [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	1,777	1,624
Mutual funds: U.S. equity large cap fund [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	48,506	47,517
Mutual funds: International equity large cap growth fund [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	33,834	31,396
Pooled funds: Japanese equity securities [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	2,536	2,116
Pooled funds: International equity securities [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	2,258	1,982
Pooled funds: Index linked U.K. equity fund [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	7,982	8,687
Pooled funds: Index linked international equity fund [Member] | Pension Plans, Defined Benefit [Member]
Fair value of plan assets	9,694	9,336
Fair Value, Inputs, Level 1 [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Fair value of plan assets	145,894	135,590
Fair Value, Inputs, Level 1 [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	163	201
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Fair value of plan assets	6,741	467
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	163	201
Fair Value, Inputs, Level 1 [Member] | Mutual funds: U.S. corporate bond fund [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Fair value of plan assets	56,813	56,210
Fair Value, Inputs, Level 1 [Member] | Mutual funds: U.S. equity large cap fund [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Fair value of plan assets	48,506	47,517
Fair Value, Inputs, Level 1 [Member] | Mutual funds: International equity large cap growth fund [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Fair value of plan assets	33,834	31,396
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	62,755	60,462
Fair Value, Inputs, Level 2 [Member] | Pooled funds: Index linked U.K. government securities fund [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	5,009	4,716
Fair Value, Inputs, Level 2 [Member] | Pooled funds: Index linked U.K. long-term government securities fund [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	11,998	10,583
Fair Value, Inputs, Level 2 [Member] | Pooled funds: Index linked U.K. corporate bonds fund [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	16,180	16,613
Fair Value, Inputs, Level 2 [Member] | Pooled funds: Japanese fixed income securities [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	5,321	4,805
Fair Value, Inputs, Level 2 [Member] | Pooled funds: International fixed income securities [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	1,777	1,624
Fair Value, Inputs, Level 2 [Member] | Pooled funds: Japanese equity securities [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	2,536	2,116
Fair Value, Inputs, Level 2 [Member] | Pooled funds: International equity securities [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	2,258	1,982
Fair Value, Inputs, Level 2 [Member] | Pooled funds: Index linked U.K. equity fund [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	7,982	8,687
Fair Value, Inputs, Level 2 [Member] | Pooled funds: Index linked international equity fund [Member] | Foreign Pension Plans, Defined Benefit [Member]
Fair value of plan assets	$ 9,694	$ 9,336