Components Of Equity - Additional Information (Detail) - $ / shares shares in Thousands		3 Months Ended
	May. 03, 2016	Mar. 31, 2016	Mar. 31, 2015
Subsequent Event
Class of Stock [Line Items]
Date of declaration of dividends	May 03, 2016
Dividend declared per share	$ 0.40
Date of dividend payment	Jun. 15, 2016
Dividends payable to shareholders date of record	Jun. 01, 2016
Non-Discretionary Plan
Class of Stock [Line Items]
Shares repurchased		423	459
Average price per share		$ 47.60	$ 47.84
Discretionary Plan
Class of Stock [Line Items]
Shares repurchased		1,048	1,158
Average price per share		$ 47.87	$ 47.87
Expected common stock shares issued and outstanding		180,000
Discretionary Plan | Subsequent Event
Class of Stock [Line Items]
Expected common stock shares issued and outstanding	170,000