Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0000824142 (http://www.sec.gov/CIK)

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Assumptions	The following weighted average assumptions were used to determine the fair value of the stock options granted on the original grant date for expense recognition purposes for options granted during December 31, 2016, 2015 and 2014 using a Black Scholes-Merton Model:     2016   2015   2014             Director and Officers:           Expected dividend yield $ 0.22   $ 0.18   N/A Expected volatility 41.19 %   44.14 %   N/A Risk-free interest rate 2.00 %   1.97 %   N/A Expected life (in years) 7.68   8.00   N/A Employees:           Expected dividend yield $ 0.25   $ 0.22   $ 0.14 Expected volatility 34.50 %   42.71 %   44.85 % Risk-free interest rate 1.73 %   1.41 %   2.26 % Expected life (in years) 5.69   8.00   8.00
Summary of Stock Options Outstanding	The following is a summary of stock options vested and exercisable as of December 31, 2016:           Weighted Average   Weighted     Range of   Number   Remaining   Average     Exercise   of   Contractual   Exercise   Intrinsic Prices   Shares   Life   Price   Value                 (in thousands) $4.54 - 20.92   338,308   4.75   $ 8.03   $ 8,465 $20.96 - 26.50   71,928   8.56   22.50   759 Total   410,236   5.42   $ 10.57   $ 9,224   The following is a summary of stock options vested and exercisable as of December 31, 2015:           Weighted Average   Weighted     Range of   Number   Remaining   Average     Exercise   of   Contractual   Exercise   Intrinsic Prices   Shares   Life   Price   Value                 (in thousands) $4.31 - 8.65   421,237   4.89   $ 7.04   $ 6,814 $8.70 - 22.76   27,134   7.82   15.31   215 Total   448,371   5.07   $ 7.54   $ 7,029 The following is a summary of stock options vested and exercisable as of December 31, 2014:           Weighted Average   Weighted     Range of   Number   Remaining   Average     Exercise   of   Contractual   Exercise   Intrinsic Prices   Shares   Life   Price   Value                 (in thousands) $3.21 - 6.89   411,553   3.46   $ 5.16   $ 7,113 $7.13 - 8.17   81,050   6.54   7.27   1,226 $8.65 - 21.14   175,527   6.53   8.76   2,392 Total   668,130   4.64   $ 6.36   $ 10,731
Summary of Stock Option Activity	A summary of option activity under the plans is as follows:         Weighted Average Exercise Options Shares   Price         Outstanding at December 31, 2015 1,130,910   $ 13.38 Granted 651,546   29.94 Exercised (257,738 )   8.00 Forfeited or Expired (74,014 )   21.92 Outstanding at December 31, 2016 1,450,704   $ 21.33 Exercisable at December 31, 2016 410,236   $ 10.57
Summary of Unvested Restricted Stock Awards	A summary of the unvested restricted stock awards is as follows:       Weighted Average Grant date Restricted stock Shares   Fair Value         Unvested at December 31, 2015 410,023   $ 18.78 Granted 136,063   23.13 Vested (119,379 )   17.81 Forfeited (18,545 )   19.60 Unvested at December 31, 2016 408,162   $ 20.47
Summary of Grant Date Fair Value of Awards During Period	2016   2015   2014 Grant date fair value of awards during the period: (in thousands) Options $ 6,102   $ 3,685   $ 817 Restricted stock 3,147   2,985   5,024 Total $ 9,249   $ 6,670   $ 5,841
Summary of Share-Based Compensation Expense	2016   2015   2014 Share-based compensation expense: (in thousands) Options $ 1,681   $ 833   $ 898 Restricted stock 2,676   2,058   1,280 Total $ 4,357   $ 2,891   $ 2,178
Summary of Income Tax Benefit Related to Share-Based Compensation	2016   2015   2014 Income tax benefit related to share-based compensation: (in thousands) Options $ 1,610   $ 2,165   $ 979 Restricted stock 458   280   260 Total $ 2,068   $ 2,445   $ 1,239