Reconciliation of Shares Used in Calculating Basic and Diluted Earnings Per Share (Detail) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Basic weighted-average shares outstanding	87,478	86,576	87,080	91,102	97,872	105,394	110,932	111,402	88,045		106,947		112,866
Effect of common stock equivalents-stock options and non-vested stock under employee compensation plans									0	[1]	966	[1]	1,129	[1]
Diluted weighted-average shares outstanding	87,478	86,576	89,955	94,416	97,872	105,967	111,937	112,637	88,045	[1]	107,913	[1]	113,995	[1]
Weighted-average anti-dilutive common stock equivalents									6,937	[1]	5,337	[1]	7,167	[1]

[1] For periods in which losses are presented, dilutive earnings per share calculations do not differ from basic earnings per share because the effects of any potential common stock equivalents are anti-dilutive and therefore not included in the calculation of dilutive earnings per share. For the year ended December 31, 2014, those potential shares totaled 3,046 which are included in the weighted average anti-dilutive common stock equivalents above, in addition to 3,891 of out of the money anti-dilutive common stock equivalents for the year ended December 31, 2014.