Share-based Payments

6 Months Ended

Mar. 31, 2019

9. Share-based Payments

The fair value of an outstanding employee stock option award is estimated on the date of grant. The expected term of the stock option granted represents the period of time the stock option is expected to be outstanding. The risk-free interest rate is based on U.S. Treasury bond rates with maturities equal to the expected term of the stock option on the grant date. The Company uses historical data as a basis to estimate the probability of forfeitures.

Stock option activity for the six months ended March 31 was as follows:


	2019			2018
	Shares of stock	Weighted average		Shares of stock	Weighted average
	under options	exercise price		under options	exercise price
	(in millions)			(in millions)
Outstanding at September 30	0.6	$	31.62	0.7	$	31.11
Options granted	—		—	—		—
Options exercised	—		—	(0.1)		27.79
Options forfeited or expired	(0.5)		31.62	—		—
Outstanding at March 31	0.1		31.62	0.6		31.62

Vested and expected to vest in the future as of March 31	0.1	$	31.62	0.6	$	31.62

The Company grants stock units to employees under its Performance Earnings Program (PEP), whereby units are earned and issued dependent upon meeting established cumulative performance objectives and vest over a three-year service period. Additionally, the Company issues restricted stock units to employees which are earned based on service conditions. The grant date fair value of PEP awards and restricted stock unit awards is that day’s closing market price of the Company’s common stock. The weighted average grant date fair value of PEP awards was $27.51 and $37.69 during the six months ended March 31, 2019 and 2018, respectively. The weighted average grant date fair value of restricted stock unit awards was $27.67 and $36.91 during the six months ended March 31, 2019 and 2018, respectively. Total compensation expense related to these share-based payments including stock options was $31.8 million and $37.2 million during the six months ended March 31, 2019 and 2018, respectively. Unrecognized compensation expense related to total share-based payments outstanding as of March 31, 2019 and September 30, 2018 was $109.0 million and $94.3 million, respectively, to be recognized on a straight-line basis over the awards’ respective vesting periods which are generally three years.