Equity (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015 |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2015 | | | $ 204,729 | |
Net earnings | $ 4,701 | $ 5,377 | 8,411 | $ 11,054 |
Foreign currency translation adjustments | 261 | $ (1,609) | 1,222 | $ (3,109) |
Pension liability adjustment, net of tax | | | 767 | |
Balance, September 30, 2016 | 200,732 | | 200,732 | |
Common Stock [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2015 | | | 10,767 | |
Net earnings | | | 0 | |
Foreign currency translation adjustments | | | 0 | |
Pension liability adjustment, net of tax | | | 0 | |
Cash dividends declared | | | 0 | |
Cash dividends paid to noncontrolling interest | | | 0 | |
Stock options exercised | | | 25 | |
Issuance of restricted stock | | | 27 | |
Stock-based compensation expense | | | 0 | |
Income tax benefit from stock options exercised | | | 0 | |
Shares purchased and retired | | | (352) | |
Balance, September 30, 2016 | 10,467 | | 10,467 | |
Capital in Excess of Par Value [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2015 | | | 45,759 | |
Net earnings | | | 0 | |
Foreign currency translation adjustments | | | 0 | |
Pension liability adjustment, net of tax | | | 0 | |
Cash dividends declared | | | 0 | |
Cash dividends paid to noncontrolling interest | | | 0 | |
Stock options exercised | | | 560 | |
Issuance of restricted stock | | | (27) | |
Stock-based compensation expense | | | 1,121 | |
Income tax benefit from stock options exercised | | | 3 | |
Shares purchased and retired | | | 0 | |
Balance, September 30, 2016 | 47,416 | | 47,416 | |
Reinvested Earnings [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2015 | | | 160,325 | |
Net earnings | | | 8,287 | |
Foreign currency translation adjustments | | | 0 | |
Pension liability adjustment, net of tax | | | 0 | |
Cash dividends declared | | | (6,568) | |
Cash dividends paid to noncontrolling interest | | | 0 | |
Stock options exercised | | | 0 | |
Issuance of restricted stock | | | 0 | |
Stock-based compensation expense | | | 0 | |
Income tax benefit from stock options exercised | | | 0 | |
Shares purchased and retired | | | (9,016) | |
Balance, September 30, 2016 | 153,028 | | 153,028 | |
Accumulated Other Comprehensive Loss [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2015 | | | (18,467) | |
Net earnings | | | 0 | |
Foreign currency translation adjustments | | | 970 | |
Pension liability adjustment, net of tax | | | 767 | |
Cash dividends declared | | | 0 | |
Cash dividends paid to noncontrolling interest | | | 0 | |
Stock options exercised | | | 0 | |
Issuance of restricted stock | | | 0 | |
Stock-based compensation expense | | | 0 | |
Income tax benefit from stock options exercised | | | 0 | |
Shares purchased and retired | | | 0 | |
Balance, September 30, 2016 | (16,730) | | (16,730) | |
Noncontrolling Interest [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2015 | | | 6,345 | |
Net earnings | | | 124 | |
Foreign currency translation adjustments | | | 252 | |
Pension liability adjustment, net of tax | | | 0 | |
Cash dividends declared | | | 0 | |
Cash dividends paid to noncontrolling interest | | | (170) | |
Stock options exercised | | | 0 | |
Issuance of restricted stock | | | 0 | |
Stock-based compensation expense | | | 0 | |
Income tax benefit from stock options exercised | | | 0 | |
Shares purchased and retired | | | 0 | |
Balance, September 30, 2016 | $ 6,551 | | $ 6,551 | |