Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Summary of Restricted Stock Award Activity (Detail)

v3.8.0.1
Stock-Based Compensation - Summary of Restricted Stock Award Activity (Detail) - Restricted Stock Awards
shares in Thousands
12 Months Ended
Sep. 30, 2017
$ / shares
shares
Number of Shares  
Beginning Balance, Nonvested, Number of Shares | shares 1,540
Granted, Number of Shares | shares 196
Vested, Number of Shares | shares (567)
Forfeited, Number of Shares | shares (32)
Ending Balance, Nonvested, Number of Shares | shares 1,137
Weighted Average Grant Date Fair Value per Share  
Beginning Balance, Nonvested, Weighted Average Grant Date Fair Value per Share (in usd per share) | $ / shares $ 10.68
Granted, Weighted Average Grant Date Fair Value per Share (in usd per share) | $ / shares 29.30
Vested, Weighted Average Grant Date Fair Value per Share (in usd per share) | $ / shares 9.94
Forfeited, Weighted Average Grant Date Fair Value per Share (in usd per share) | $ / shares 9.81
Ending Balance, Nonvested, Weighted Average Grant Date Fair Value per Share (in usd per share) | $ / shares $ 14.34