GUARANTOR - Condensed Shareholder's Equity (Details) - USD ($)
$ in Thousands |
3 Months Ended |
12 Months Ended |
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
$ 329,021
|
|
|
|
$ 298,393
|
$ 329,021
|
$ 298,393
|
$ 269,494
|
| Net income (loss) |
$ 14,088
|
$ 8,442
|
$ 6,747
|
(93)
|
$ 10,850
|
$ 6,473
|
$ 8,137
|
1,363
|
29,184
|
26,823
|
26,024
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
5,524
|
5,232
|
4,270
|
| Issuance of common stock related to an incentive plan VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Common stock repurchase VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
$ (1,562)
|
$ (1,514)
|
$ (1,640)
|
| Purchase of vested employee restricted stock units SHARES |
|
|
|
|
|
|
|
|
(132,000)
|
(142,000)
|
(186,000)
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 5
|
$ 0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
$ 0
|
|
0
|
| Exercise of stock options SHARES |
|
|
|
|
|
|
|
|
11,750
|
|
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
$ 35
|
82
|
245
|
| Ending Balance VALUE |
$ 361,450
|
|
|
|
$ 329,021
|
|
|
|
361,450
|
329,021
|
298,393
|
| PreferredStockDividendsIncomeStatementImpact |
|
|
|
|
|
|
|
|
752
|
0
|
0
|
| Common Class A [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
$ 319
|
|
|
|
$ 313
|
$ 319
|
$ 313
|
$ 312
|
| Opening Balance SHARES |
|
|
|
31,862,294
|
|
|
|
31,308,194
|
31,862,294
|
31,308,194
|
31,226,047
|
| Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
738,195
|
638,102
|
96,560
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
$ 7
|
$ 7
|
$ 1
|
| Stock Issued During Period Shares Employee Stock Purchase Plans |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Issuance of common stock related to an incentive plan VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Common stock repurchase SHARES |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Common stock repurchase VALUE |
|
|
|
|
|
|
|
|
0
|
$ 0
|
$ 0
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
$ (1)
|
$ (1)
|
$ (2)
|
| Purchase of vested employee restricted stock units SHARES |
|
|
|
|
|
|
|
|
(131,688)
|
(141,502)
|
(186,038)
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
$ 0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
|
| Exercise of stock options SHARES |
|
|
|
|
|
|
|
|
11,750
|
57,500
|
171,625
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 2
|
| Ending Balance SHARES |
32,480,551
|
|
|
|
31,862,294
|
|
|
|
32,480,551
|
31,862,294
|
31,308,194
|
| Ending Balance VALUE |
$ 325
|
|
|
|
$ 319
|
|
|
|
$ 325
|
$ 319
|
$ 313
|
| Common Class B [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
$ 72
|
|
|
|
$ 72
|
$ 72
|
$ 72
|
$ 72
|
| Opening Balance SHARES |
|
|
|
7,197,532
|
|
|
|
7,197,532
|
7,197,532
|
7,197,532
|
7,197,532
|
| Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Stock Issued During Period Shares Employee Stock Purchase Plans |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Issuance of common stock related to an incentive plan VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Common stock repurchase SHARES |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Common stock repurchase VALUE |
|
|
|
|
|
|
|
|
0
|
$ 0
|
$ 0
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Purchase of vested employee restricted stock units SHARES |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Exercise of stock options SHARES |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Ending Balance SHARES |
7,197,532
|
|
|
|
7,197,532
|
|
|
|
7,197,532
|
7,197,532
|
7,197,532
|
| Ending Balance VALUE |
$ 72
|
|
|
|
$ 72
|
|
|
|
$ 72
|
$ 72
|
$ 72
|
| Additional Paid In Capital [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
$ 608,515
|
|
|
|
$ 604,721
|
608,515
|
604,721
|
601,847
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
5,517
|
5,225
|
4,269
|
| Issuance of common stock related to an incentive plan VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Common stock repurchase VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
(1,561)
|
(1,513)
|
(1,638)
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
35
|
82
|
243
|
| Ending Balance VALUE |
611,754
|
|
|
|
608,515
|
|
|
|
611,754
|
608,515
|
604,721
|
| PreferredStockDividendsIncomeStatementImpact |
|
|
|
|
|
|
|
|
752
|
|
|
| Retained Earnings [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
(279,885)
|
|
|
|
(306,713)
|
(279,885)
|
(306,713)
|
(332,737)
|
| Net income (loss) |
|
|
|
|
|
|
|
|
29,184
|
26,823
|
26,024
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Issuance of common stock related to an incentive plan VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Common stock repurchase VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
0
|
5
|
0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Ending Balance VALUE |
(250,701)
|
|
|
|
(279,885)
|
|
|
|
(250,701)
|
(279,885)
|
(306,713)
|
| Parent Company [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
329,021
|
|
|
|
298,393
|
329,021
|
298,393
|
269,494
|
| Net income (loss) |
|
|
|
|
|
|
|
|
29,184
|
26,823
|
26,024
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
5,524
|
5,232
|
4,270
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
(1,562)
|
(1,514)
|
(1,640)
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
0
|
5
|
0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
$ 0
|
0
|
0
|
| Exercise of stock options SHARES |
|
|
|
|
|
|
|
|
11,750
|
|
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
$ 35
|
82
|
245
|
| Ending Balance VALUE |
$ 361,450
|
|
|
|
$ 329,021
|
|
|
|
361,450
|
329,021
|
298,393
|
| PreferredStockDividendsIncomeStatementImpact |
|
|
|
|
|
|
|
|
752
|
0
|
0
|
| Parent Company [Member] | Common Class A [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
$ 319
|
|
|
|
$ 313
|
$ 319
|
$ 313
|
$ 312
|
| Opening Balance SHARES |
|
|
|
31,862,294
|
|
|
|
31,308,194
|
31,862,294
|
31,308,194
|
31,226,047
|
| Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
738,195
|
638,102
|
96,560
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
$ 7
|
$ 7
|
$ 1
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
$ (1)
|
$ (1)
|
$ (2)
|
| Purchase of vested employee restricted stock units SHARES |
|
|
|
|
|
|
|
|
(131,688)
|
(141,502)
|
(186,038)
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Exercise of stock options SHARES |
|
|
|
|
|
|
|
|
0
|
57,500
|
171,625
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 2
|
| Ending Balance SHARES |
32,480,551
|
|
|
|
31,862,294
|
|
|
|
32,480,551
|
31,862,294
|
31,308,194
|
| Ending Balance VALUE |
$ 325
|
|
|
|
$ 319
|
|
|
|
$ 325
|
$ 319
|
$ 313
|
| Parent Company [Member] | Common Class B [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
$ 72
|
|
|
|
$ 72
|
$ 72
|
$ 72
|
$ 72
|
| Opening Balance SHARES |
|
|
|
7,197,532
|
|
|
|
7,197,532
|
7,197,532
|
7,197,532
|
7,197,532
|
| Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Purchase of vested employee restricted stock units SHARES |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
0
|
$ 0
|
$ 0
|
| Exercise of stock options SHARES |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
$ 0
|
$ 0
|
$ 0
|
| Ending Balance SHARES |
7,197,532
|
|
|
|
7,197,532
|
|
|
|
7,197,532
|
7,197,532
|
7,197,532
|
| Ending Balance VALUE |
$ 72
|
|
|
|
$ 72
|
|
|
|
$ 72
|
$ 72
|
$ 72
|
| Parent Company [Member] | Additional Paid In Capital [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
$ 608,515
|
|
|
|
$ 604,721
|
608,515
|
604,721
|
601,847
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
5,517
|
5,225
|
4,269
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
(1,561)
|
(1,513)
|
(1,638)
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
35
|
82
|
243
|
| Ending Balance VALUE |
611,754
|
|
|
|
608,515
|
|
|
|
611,754
|
608,515
|
604,721
|
| PreferredStockDividendsIncomeStatementImpact |
|
|
|
|
|
|
|
|
752
|
|
|
| Parent Company [Member] | Retained Earnings [Member] |
|
|
|
|
|
|
|
|
|
|
|
| Condensed Financial Statements, Captions [Line Items] |
|
|
|
|
|
|
|
|
|
|
|
| Opening Balance VALUE |
|
|
|
$ (279,885)
|
|
|
|
$ (306,713)
|
(279,885)
|
(306,713)
|
(332,737)
|
| Net income (loss) |
|
|
|
|
|
|
|
|
29,184
|
26,823
|
26,024
|
| Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Purchase of vested employee restricted stock units |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Forfeitures of dividend equivalents VALUE |
|
|
|
|
|
|
|
|
0
|
5
|
0
|
| Realization of tax benefit for dividend equivalent payments VALUE |
|
|
|
|
|
|
|
|
|
0
|
0
|
| Net unrealized gain (loss) on derivatives VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Exercise of stock options VALUE |
|
|
|
|
|
|
|
|
0
|
0
|
0
|
| Ending Balance VALUE |
$ (250,701)
|
|
|
|
$ (279,885)
|
|
|
|
$ (250,701)
|
$ (279,885)
|
$ (306,713)
|