Segment Reporting - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013 Country	Sep. 30, 2012 Country	Sep. 30, 2013 Country	Sep. 30, 2012 Country	Dec. 31, 2012 Country
Segment Reporting [Abstract]
Number of outside countries accounted for Company's consolidated revenue	0	0	0	0
Minimum percentage of Company's consolidated revenue accounted by outside countries	1.00%	1.00%	1.00%	1.00%
Number of outside countries accounted for Company's consolidated long-term asset	0		0		0
Minimum percentage of Company's consolidated long term assets	1.00%		1.00%		1.00%