Equity-Based Compensation - Summary of Performance Share Award 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	355,309
Performance Share Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding at beginning of year	265,829	306,261	250,596
Shares, Granted	187,794	72,470	62,874
Shares, Released	(253,484)	(1,802)	(7,209)
Shares, Forfeited	(4,980)	(111,100)	0
Shares, Outstanding at end of period	195,159	265,829	306,261
Weighted-Average Grant Date Fair Value, Outstanding at beginning of year	$ 35.55	$ 28.58	$ 25.35
Weighted-Average Grant Date Fair Value, Granted	$ 35.17	$ 38.68	$ 41.47
Weighted-Average Grant Date Fair Value, Released	$ 27.90	$ 41.57	$ 28.79
Weighted-Average Grant Date Fair Value, Forfeited	$ 41.46	$ 23.06	$ 0.00
Weighted-Average Grant Date Fair Value, Outstanding at end of period	$ 42.25	$ 35.55	$ 28.58