Incentive Share-Based Plan and Other Employee Benefits - Additional Information (Details) - USD ($)
|
6 Months Ended |
12 Months Ended |
Jun. 30, 2014 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
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| Fair value of option granted per share |
|
$ 2.26
|
$ 2.65
|
$ 2.01
|
| Total intrinsic value of options exercised |
|
$ 3,500,000
|
$ 1,600,000
|
$ 761,000
|
| Unrecognized compensation expense |
|
$ 484,000
|
|
|
| Unrecognized compensation expense, weighted-average period |
|
1 year 2 months 12 days
|
|
|
| Employer contribution to savings plan |
|
$ 778,000
|
708,000
|
670,000
|
| Profit sharing contribution |
|
$ 600,000
|
600,000
|
450,000
|
| Options [Member] |
|
|
|
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
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|
|
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| Reduction in shares issued upon exercises |
|
47,412
|
|
|
| Share-based compensation expense |
|
$ 544,000
|
$ 485,000
|
$ 221,000
|
| Risk free interest rate, minimum |
|
0.10%
|
0.10%
|
0.10%
|
| Risk free interest rate, maximum |
|
1.60%
|
1.60%
|
1.60%
|
| Volatility index, minimum |
|
13.30%
|
13.30%
|
13.30%
|
| Volatility index, maximum |
|
29.90%
|
29.90%
|
29.90%
|
| Restricted Stock Units [Member] |
|
|
|
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| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
| Total intrinsic value |
|
$ 244,000
|
$ 56,000
|
|
| 2014 Share-Based Incentive Plan [Member] |
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|
|
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| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
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|
|
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| Maximum number of shares available for issuance under the plan |
800,000
|
|
|
|
| Maximum | Options [Member] |
|
|
|
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| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
| Expected annual dividend yield |
|
2.30%
|
2.30%
|
2.30%
|
| Expected term |
|
6 years 6 months
|
6 years 6 months
|
6 years 6 months
|
| Maximum | 2014 Share-Based Incentive Plan [Member] |
|
|
|
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
| Share-based awards granted term |
10 years
|
|
|
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| Minimum | Options [Member] |
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|
|
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| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
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| Expected annual dividend yield |
|
0.70%
|
0.70%
|
0.70%
|
| Expected term |
|
8 months 12 days
|
8 months 12 days
|
8 months 12 days
|