Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity, Stock Options and Net Income per Share - Non-employee Director Non-vested Shares (Details)

v3.3.1.900
Shareholders' Equity, Stock Options and Net Income per Share - Non-employee Director Non-vested Shares (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Non-Vested Shares [Line Items]      
Share-based compensation $ 7,486 $ 6,681 $ 6,178
Nonemployee Director Nonvested Shares Granted [Member]      
Non-Vested Shares [Line Items]      
Non-vested share vesting period 1 year    
Outstanding at beginning of year (shares) 15 15 20
Granted (shares) 14 15 15
Vested (shares) (14) (15) (20)
Outstanding at end of year (shares) 15 15 15
Weighted average grant date fair value of non-vested shares at beginning of year $ 44 $ 38 $ 32
Weighted Average Grant Date Fair Value 51 44 38
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value 43 38 32
Weighted average grant date fair value non-vested shares at end of year $ 51 $ 44 $ 38
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted in Period, Total Fair Value $ 740 $ 650 $ 560
Grant date fair value of shares that vested during the year 727 632 762
Share-based compensation 661 589 589
Tax benefit related to share-based compensation expense 259 $ 225 $ 225
Unrecognized compensation cost $ 286