Equity-Based Compensation - Summary of SAR Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Granted	0	0	0
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding at beginning of year	1,535,804	1,287,724	1,234,787
Shares, Granted	326,811	431,040	387,847
Shares, Exercised	(376,673)	(102,972)	(95,672)
Shares, Forfeited	(80,515)	(75,978)	(238,965)
Shares, Expired	(2,643)	(4,010)	(273)
Shares, Outstanding at end of period	1,402,784	1,535,804	1,287,724
Shares, Exercisable at end of period	520,426	514,787	305,228
Weighted-Average Exercise Price, Outstanding at beginning of year	$ 31.66	$ 28.91	$ 23.82
Weighted-Average Exercise Price, Granted	$ 46.13	$ 38.51	$ 41.14
Weighted-Average Exercise Price, Exercised	$ 25.44	$ 23.83	$ 22.20
Weighted-Average Exercise Price, Forfeited	$ 37.54	$ 34.10	$ 25.15
Weighted-Average Exercise Price, Expired	$ 33.70	$ 41.57	$ 19.56
Weighted-Average Exercise Price, Outstanding at end of year	$ 36.36	$ 31.66	$ 28.91
Weighted-Average Exercise Price, Exercisable at end of year	$ 30.51	$ 26.52	$ 23.27
Intrinsic value of exercised options and SARs	$ 7,900,000	$ 1,500,000	$ 1,700,000