Summary of Option Activity of Incentive Award (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]
Outstanding, January 1,	32,265	38,932	56,267
Expired	26,516	6,667	17,335
Exercised	0	0	0
Outstanding, December 31,	5,749	32,265	38,932
Options exercisable at December 31,	5,749	32,265	38,932
Outstanding, January 1,	$ 70.38	$ 68.34	$ 67.50
Expired	$ 68.46	$ 58.49	$ 65.61
Exercised	$ 0	$ 0	$ 0
Outstanding, December 31,	$ 79.20	$ 70.38	$ 68.34
Options exercisable at December 31,