Earnings per Share (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted average number of shares for calculation of basic EPS – Common Stock	35,411,608	33,652,646	28,352,864
Stock options under the 1997, 2006, 2011 and 2013 equity plans	637,723	470,995	509,599
Weighted average number of shares for calculation of diluted EPS – Common Stock	36,049,331	34,123,641	28,862,463
Common stock that have been excluded from the diluted shares calculation	155,000	550,000	1,680,891
Stock options outstanding for the 1997, 2006, 2011 and 2013 equity plans
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock that have been excluded from the diluted shares calculation	155,000	550,000	149,000
Series C Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock that have been excluded from the diluted shares calculation			1,531,891