Stock-Based Compensation and Stock Awards - Summary of PSA Activity (Detail)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Restricted Stock
Nonvested options, Beginning Balance (in shares) | shares	403,179
Granted (in shares) | shares	186,730
Vested (in shares) | shares	(218,180)
Nonvested options, Ending Balance (in shares) | shares	348,690
Weighted Average Remaining Contractual Life (in years)
Nonvested Weighted Average Grant Date Fair Value, Beginning Balance (in dollars per share) | $ / shares	$ 43.18
Granted (in dollars per share) | $ / shares	44.35
Vested (in dollars per share) | $ / shares	44.22
Nonvested Weighted Average Grant Date Fair Value, Ending Balance (in dollars per share) | $ / shares	$ 43.16
Performance Unit Awards
Restricted Stock
Nonvested options, Beginning Balance (in shares) | shares	288,093
Granted (in shares) | shares	183,471
Vested (in shares) | shares	(203,014)
Nonvested options, Ending Balance (in shares) | shares	268,550
Weighted Average Remaining Contractual Life (in years)
Nonvested Weighted Average Grant Date Fair Value, Beginning Balance (in dollars per share) | $ / shares	$ 54.22
Granted (in dollars per share) | $ / shares	48.47
Vested (in dollars per share) | $ / shares	53.46
Nonvested Weighted Average Grant Date Fair Value, Ending Balance (in dollars per share) | $ / shares	$ 52.81