Capital Transactions (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Subsidiary Sale Of Stock [Line Items]
Number of common stock	76,000
Payroll taxes in form of stock	$ 538
Proceeds from exercise of stock options	2,294	$ 1,375
Proceeds from sale of stock under employee stock purchase plan	$ 806	$ 345
Employee Stock
Subsidiary Sale Of Stock [Line Items]
Treasury stock reissued, shares	22,000
Proceeds from sale of stock under employee stock purchase plan	$ 806
Stock Options
Subsidiary Sale Of Stock [Line Items]
Treasury stock reissued, shares	53,000
Common Stock
Subsidiary Sale Of Stock [Line Items]
Common stock issued from exercise of stock options, shares	449,000
Stock issued due to vesting of restricted stock award, shares	72,000
Common stock issued under the employee stock purchase plan, shares	63,000
Treasury Stock
Subsidiary Sale Of Stock [Line Items]
Common stock issued from exercise of stock options, shares	53,000
Stock issued due to vesting of restricted stock award, shares	1,000
Common stock issued under the employee stock purchase plan, shares	22,000