Pensions and Other Postretirement Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended		9 Months Ended
	Dec. 31, 2014 Scenario, Forecast [Member] Minimum [Member]	Dec. 31, 2014 Scenario, Forecast [Member] Maximum [Member]	Sep. 30, 2014 Pension Plans [Member]	Sep. 30, 2013 Pension Plans [Member]	Sep. 30, 2014 Other Postretirement Benefits [Member]	Sep. 30, 2013 Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost			$ 2,521	$ 2,526	$ 236	$ 789
Interest cost			7,217	5,999	2,057	2,374
Expected return on assets			(7,260)	(6,103)
Amortization of prior service cost/(credit)			41	27	(3,366)	(2,818)
Amortization of transition obligation				51
Amortization of net actuarial loss			1,845	2,357	2,181	2,606
Curtailment			(710)
Settlement	(5,000)	(10,000)		315
Net periodic benefit cost			$ 3,654	$ 5,172	$ 1,108	$ 2,951