Equity - Schedule of Stock Options, SARs, and Non-vested Restricted Stock Outstanding (Details) - $ / shares
|
12 Months Ended |
|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
Dec. 31, 2012 |
| Equity [Abstract] |
|
|
|
|
| Number of Outstanding of Stock Options and SARs |
747,573
|
718,143
|
664,245
|
788,748
|
| Stock Options and SARs Outstanding, Weighted Average Exercise Price |
$ 26.68
|
$ 25.12
|
$ 23.78
|
$ 20.89
|
| Stock Options and SARs Grants in Period, Net of Forfeitures |
119,110
|
87,600
|
94,017
|
|
| Stock Options and SARs Grants in Period, Weighted Average Exercise Price |
$ 32.25
|
$ 34.92
|
$ 31.24
|
|
| Stock Options and SARs Exercises in Period |
86,680
|
23,035
|
208,877
|
|
| Stock Options and SARs Exercises in Period, Weighted Average Exercise Price |
$ 21.32
|
$ 20.83
|
$ 16.24
|
|
| Stock Options and SARs Forfeitures and Expirations in Period |
3,000
|
10,667
|
9,643
|
|
| Stock Options and SARs Forfeitures and Expirations in Period, Weighted Average Exercise Price |
$ 30.05
|
$ 31.16
|
$ 23.02
|
|
| Exercisable Number of Stock Options and SARs |
543,698
|
548,180
|
483,216
|
|
| Stock Options and SARs Exercisable, Weighted Average Exercise Price |
$ 24.34
|
$ 23.12
|
$ 22.83
|
|
| Outstanding Non-Vested Restricted Stock |
132,651
|
103,772
|
98,285
|
91,311
|
| Restricted Stock, Nonvested, Weighted Average Grant Date Fair Value |
$ 32.12
|
$ 31.24
|
$ 27.66
|
$ 18.75
|
| Restricted Stock, Grants in Period |
76,616
|
57,590
|
73,985
|
|
| Restricted Stock Awarded, Weighted Average Grant Date Fair Value |
$ 32.14
|
$ 33.88
|
$ 30.27
|
|
| Restricted Stock, Forfeited in Period |
0
|
8,360
|
1,000
|
|
| Restricted Stock, Forfeitures, Weighted Average Grant Date Fair Value |
$ 0.00
|
$ 21.72
|
$ 31.42
|
|
| Restricted Stock, Net of Forfeitures Stock Issued During Period, Shares, |
47,737
|
43,743
|
66,011
|
|
| Restricted Stock, Vested in Period, Weighted Average Grant Date Fair Value |
$ 30.25
|
$ 28.48
|
$ 18.21
|
|