Pension Plan (Details 3)	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2018
Retirement Benefits [Abstract]
Discount rate	2.10%	2.90%
Expected return on assets	3.00%	3.70%
RPI inflation	3.00%	3.20%
CPI inflation	2.10%	2.20%
Pension increases - pre-2006 service	2.90%	3.10%
Pension increases - post-2006 service	2.10%	2.20%