Common Stock and Treasury Stock - Additional Information (Detail) - USD ($)	12 Months Ended			60 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Feb. 28, 2014	Jul. 31, 2013	Sep. 13, 2012	Sep. 12, 2012
Maximum stock authorized to purchase under stock repurchase program					$ 200,000,000			$ 262,100,000
Increase in maximum stock authorized to purchase under stock repurchase program					$ 100,000,000	$ 100,000,000
Repurchase of common stock, shares	3,020,926		3,578,427	40,129,393
Repurchase of common stock, value	$ 60,089,000		$ 70,000,000	$ 455,900,000
Number shares issued pursuant to stock option exercises	792,841	1,144,273	2,036,558
Long-term incentive program performance share awards
Stock issued during the period performance share award	470,029	548,671	635,643
Restricted share awards (RSAs) [Member]
Stock issued during period, performance based restricted share awards	148,322	125,026	106,275
Performance-Based Restricted Share Awards [Member]
Stock issued during period, performance based restricted share awards		978,365
Stock Options [Member]
Number shares issued pursuant to stock option exercises	797,140	1,146,199	2,037,467
Maximum
Maximum stock authorized to purchase under stock repurchase program							$ 113,000,000
Stock authorized to purchase under stock repurchase program, shares							7,500,000
Remaining value of shares authorized for purchase under the stock repurchase program	$ 78,200,000			$ 78,200,000