Share-Based Employee Compensation - Shares Authorized, Available for Future Grant and Outstanding Under Each Plans (Detail)	Dec. 31, 2019 shares
Equity Incentive Plan [Line Items]
Authorized (in shares)	34,000,000
Available (in shares)	9,643,000
Outstanding (in shares)	2,727,000
2004 Plan
Equity Incentive Plan [Line Items]
Authorized (in shares)	33,000,000
Available (in shares)	9,003,000
Outstanding (in shares)	2,671,000
2013 Directors Plan
Equity Incentive Plan [Line Items]
Authorized (in shares)	1,000,000
Available (in shares)	640,000
Outstanding (in shares)	56,000