Components of Calculation of Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2015	[2]	Sep. 30, 2015	[2]	Jun. 30, 2015	[2]	Mar. 31, 2015	[2]	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income	$ 23,694		$ 69,770		$ 33,315		$ 26,572		$ 26,549		$ 70,316		$ 42,244		$ 33,304		$ 153,351	$ 172,413	$ 182,391
Weighted average number of shares used in:
Basic earnings per share																	59,866	61,021	63,426
Dilutive common stock equivalents:
Restricted stock units																	383	285	319
Diluted earnings per share																	60,249	61,306	63,745

[1] The first, second, third and fourth quarters of 2016 include rationalization charges of $1.1 million, $5.0 million, $7.8 million and $5.1 million, respectively. The fourth quarter of 2016 includes costs attributed to announced acquisitions of $1.4 million.

[2] The first, second, third and fourth quarters of 2015 include rationalization charges of $0.7 million, $1.0 million, $9.1 million and $3.6 million, respectively.