Pension and Retirement Plans (Detail) - Components of net periodic benefit costs - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Pension:
Pension:
Service cost	$ 10	$ 9	$ 19	$ 18
Interest cost	104	157	210	319
Expected return on plan assets	(65)	(92)	(131)	(190)
Amortization of:
Prior service gain	0	0	0	0
Amortization of net gain (loss)	90	43	180	87
Net periodic benefit cost	139	117	278	234
Post Retirement:
Pension:
Service cost	10	7	19	14
Interest cost	10	11	22	21
Amortization of:
Amortization of net gain (loss)	4	(20)	8	(40)
Net periodic benefit cost	24	(2)	49	(5)
Foreign | Pension:
Pension:
Service cost	10	9	19	18
Interest cost	93	146	188	297
Expected return on plan assets	(65)	(92)	(131)	(190)
Amortization of:
Prior service gain	0	0	0	0
Amortization of net gain (loss)	91	44	182	89
Net periodic benefit cost	129	107	258	214
Foreign | Post Retirement:
Pension:
Service cost	0	0	0	0
Interest cost	0	0	0	0
Amortization of:
Amortization of net gain (loss)	0	0	0	0
Net periodic benefit cost	0	0	0	0
U.S. | Pension:
Pension:
Service cost	0	0	0	0
Interest cost	11	11	22	22
Expected return on plan assets	0	0	0	0
Amortization of:
Prior service gain	0	0	0	0
Amortization of net gain (loss)	(1)	(1)	(2)	(2)
Net periodic benefit cost	10	10	20	20
U.S. | Post Retirement:
Pension:
Service cost	10	7	19	14
Interest cost	10	11	22	21
Amortization of:
Amortization of net gain (loss)	4	(20)	8	(40)
Net periodic benefit cost	$ 24	$ (2)	$ 49	$ (5)