Equity (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2014 | | | $ 197,954 | |
Net earnings | $ 5,377 | $ 5,545 | 11,054 | $ 11,296 |
Foreign currency translation adjustments | (1,609) | $ (1,426) | (3,109) | $ (796) |
Pension liability adjustment, net of tax | | | 815 | |
Balance, September 30, 2015 | 199,818 | | 199,818 | |
Common Stock [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2014 | | | 10,821 | |
Net earnings | | | 0 | |
Foreign currency translation adjustments | | | 0 | |
Pension liability adjustment, net of tax | | | 0 | |
Cash dividends declared | | | 0 | |
Stock options exercised | | | 138 | |
Issuance of restricted stock | | | 22 | |
Stock-based compensation expense | | | 0 | |
Income tax benefit from stock options exercised | | | 0 | |
Shares purchased and retired | | | (172) | |
Balance, September 30, 2015 | 10,809 | | 10,809 | |
Capital in Excess of Par Value [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2014 | | | 37,966 | |
Net earnings | | | 0 | |
Foreign currency translation adjustments | | | 0 | |
Pension liability adjustment, net of tax | | | 0 | |
Cash dividends declared | | | 0 | |
Stock options exercised | | | 2,558 | |
Issuance of restricted stock | | | (22) | |
Stock-based compensation expense | | | 1,112 | |
Income tax benefit from stock options exercised | | | 461 | |
Shares purchased and retired | | | 0 | |
Balance, September 30, 2015 | 42,075 | | 42,075 | |
Reinvested Earnings [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2014 | | | 160,179 | |
Net earnings | | | 11,199 | |
Foreign currency translation adjustments | | | 0 | |
Pension liability adjustment, net of tax | | | 0 | |
Cash dividends declared | | | (6,405) | |
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 | | | (4,588) | |
Balance, September 30, 2015 | 160,385 | | 160,385 | |
AOCI Attributable to Parent [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2014 | | | (18,030) | |
Net earnings | | | 0 | |
Foreign currency translation adjustments | | | (2,408) | |
Pension liability adjustment, net of tax | | | 815 | |
Cash dividends declared | | | 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, 2015 | (19,623) | | (19,623) | |
Noncontrolling Interest [Member] | | | | |
Stockholders Equity Note [Line Items] | | | | |
Balance, December 31, 2014 | | | 7,018 | |
Net earnings | | | (145) | |
Foreign currency translation adjustments | | | (701) | |
Pension liability adjustment, net of tax | | | 0 | |
Cash dividends declared | | | 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, 2015 | $ 6,172 | | $ 6,172 | |