Outstanding Common Stock Equivalents That Were Anti-Dilutive Tickmarks (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Anti-dilutive Non-Vested Stock Weighted Average Grant Date Fair Value	$ 39.48	$ 48.66	$ 38.40