Fair Value Measurements (Details) (Total, USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Level 3
Assets:
Total fair value	$ 0	$ 0
Fair value measurements on recurring basis
Assets:
Total fair value	262,833	274,439
Fair value measurements on recurring basis | Cash and money market funds
Assets:
Total fair value	45,871	68,326
Fair value measurements on recurring basis | Defined Benefit Pension Plans
Assets:
Total fair value	216,962	206,113
Fair value measurements on recurring basis | Level 1
Assets:
Total fair value	87,839	106,901
Fair value measurements on recurring basis | Level 1 | Cash and money market funds
Assets:
Total fair value	45,871	68,326
Fair value measurements on recurring basis | Level 1 | Defined Benefit Pension Plans
Assets:
Total fair value	41,968	38,575
Fair value measurements on recurring basis | Level 2
Assets:
Total fair value	174,994	167,538
Fair value measurements on recurring basis | Level 2 | Defined Benefit Pension Plans
Assets:
Total fair value	$ 174,994	$ 167,538