XML 46 R42.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Equity-Based Compensation (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2014
Share-based Compensation [Abstract] |
Schedule of Number of Awards and Weighted Average Grant Date Fair Value | The following table provides the number of restricted stock units (that will convert to shares upon vesting) and shares of restricted stock that were issued during the years ended December 31 along with the weighted-average grant-date fair value of each award:
| 2014 |  | 2013 |  | 2012
Awards | Number of Awards |  | Weighted Average Grant Date Fair Value |  | Number of Awards |  | Weighted Average Grant Date Fair Value |  | Number of Awards |  | Weighted Average Grant Date Fair Value
Restricted stock units | 218,857 |  |  | $ | 16.96 |  |  | 150,570 |  |  | $ | 14.60 |  |  | 151,452 |  |  | $ | 13.58 |
Restricted shares | 21,721 |  |  | $ | 16.76 |  |  | 13,188 |  |  | $ | 16.83 |  |  | 11,130 |  |  | $ | 11.86 |
Summary of Compensation Expense Connection with Awards | The Company recognized the following compensation expense in connection with awards that vested under the 2005 Equity Incentive Plan and previously terminated plans along with the related tax benefits recognized during the years ended December 31 (in thousands):
| 2014 |  | 2013 |  | 2012
Expense recognized under terminated plans | $ | — |  |  | $ | — |  |  | $ | 18 |
Expense recognized under the Plan | 3,150 |  |  | 2,564 |  |  | 3,130 |
Total stock compensation expense | $ | 3,150 |  |  | $ | 2,564 |  |  | $ | 3,148 |
Tax benefits recognized related to stock compensation expense | $ | 1,229 |  |  | $ | 1,000 |  |  | $ | 1,228 |
Summary of Ranges of Outstanding and Exercisable Options | The following table summarizes the ranges of outstanding and exercisable options at December 31, 2014:
Range of Exercise Prices | Options Outstanding |  | Weighted Average Remaining Contractual Life (in years) |  | Weighted Average Exercise Price |  | Options Exercisable |  | Weighted Average Exercise Price
$8.90 – $8.90 | 59,175 |  |  | 5.70 |  | $ | 8.90 |  |  | 59,175 |  |  | $ | 8.90 |
$9.74 – $9.74 | 157,264 |  |  | 6.70 |  | $ | 9.74 |  |  | 113,514 |  |  | $ | 9.74 |
$11.89 – $18.78 | 148,781 |  |  | 3.54 |  | $ | 15.98 |  |  | 148,781 |  |  | $ | 15.98 |
$20.52 – $23.78 | 204,099 |  |  | 2.35 |  | $ | 22.56 |  |  | 204,099 |  |  | $ | 22.56 |
| 569,319 |  |  |  |  |  |  | 525,569 |  |  |
Summary of Stock Options Transactions | The following table summarizes information about stock option transactions:
| Options |  | Weighted Average Exercise Price |  | Weighted Average Remaining Contractual Life (in years) |  | Aggregate Intrinsic Value
Balance at January 1, 2012 | 770,499 |  |  | $ | 14.74 |  |  |  |  |
Exercised | (27,500 | ) |  | 9.70 |  |  |  |  |
Forfeited | (31,375 | ) |  | 13.76 |  |  |  |  |
Balance at December 31, 2012 | 711,624 |  |  | $ | 14.97 |  |  |  |  |
Exercised | (59,750 | ) |  | 11.00 |  |  |  |  |
Forfeited | (29,750 | ) |  | 12.38 |  |  |  |  |
Balance at December 31, 2013 | 622,124 |  |  | $ | 15.48 |  |  |  |  |
Exercised | (52,805 | ) |  | 11.18 |  |  |  |  |
Balance at December 31, 2014 | 569,319 |  |  | $ | 15.88 |  |  | 4.00 |  | $ | 1,393,000 |
Aggregate Intrinsic Value of Options Exercised and Aggregate Fair Value of Restricted Stock Units and Restricted Shares that Vested | The following table sets forth the aggregate intrinsic value of options exercised and aggregate fair value of restricted stock units and restricted shares that vested during the years ended December 31 (in thousands):
| 2014 |  | 2013 |  | 2012
Aggregate intrinsic value of options exercised | $ | 326 |  |  | $ | 398 |  |  | $ | 115 |
Aggregate fair value of vested restricted stock units | $ | 2,416 |  |  | $ | 1,900 |  |  | $ | 2,760 |
Aggregate fair value of vested restricted shares | $ | 364 |  |  | $ | 222 |  |  | $ | 193 |
Summary of Information About Restricted Stock Units and Weighted Average Grant Date Fair Value | The following table summarizes information about non-vested restricted stock units (that will convert to shares upon vesting) and restricted shares:
| Restricted Stock Units |  | Weighted Average Grant Date Fair Value |  | Restricted Shares |  | Weighted Average Grant Date Fair Value
Balance at December 31, 2013 | 576,724 |  |  | $ | 14.77 |  |  | 5,053 |  |  | $ | 14.37 |
Granted | 218,857 |  |  | 16.96 |  |  | 21,721 |  |  | 16.76 |
Vested | (136,110 | ) |  | 16.13 |  |  | (16,515 | ) |  | 16.57 |
Forfeited | (11,979 | ) |  | 13.21 |  |  | — |  |  | — |
Balance at December 31, 2014 | 647,492 |  |  | 15.26 |  |  | 10,259 |  |  | 15.89 |
Schedule of Compensation Expense Recognized from Change in Fair Value and Vesting of Performance Stock Units | The following table summarizes the compensation expense recognized from the change in fair value and vesting of performance stock units awarded for the years ended December 31 (in thousands):
| 2014 |  | 2013 |  | 2012
Performance stock unit compensation expense | $ | 31 |  |  | $ | 2,214 |  |  | $ | 1,639 |
Cash Paid to Settle Liability Awards | The MSPP is a share-based liability settled in cash. The following table sets forth the cash paid to settle these liability awards and expense recognized for the years ended December 31 (in thousands):
| 2014 |  | 2013 |  | 2012
Share-based liabilities paid | $ | 2,120 |  |  | $ | 531 |  |  | $ | 542 |
MSPP expense | $ | 329 |  |  | $ | 3,857 |  |  | $ | 1,180 |

X
- Definition Cash Paid To Settle Liability Awards [Table Text Block] + References No definition available. + Details
Name: | rock_CashPaidToSettleLiabilityAwardsTableTextBlock
Namespace Prefix: | rock_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of compensation expense recognized from change in fair value and vesting of performance stock units [Table text block]. + References No definition available. + Details
Name: | rock_ScheduleOfCompensationExpenseRecognizedFromChangeInFairValueAndVestingOfPerformanceStockUnitsTableTextBlock
Namespace Prefix: | rock_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of the intrinsic value of options exercised and fair value of restricted stock and restricted stock units vested during the period. + References No definition available. + Details
Name: | rock_ScheduleOfFairValueOfOptionsExercisedAndOtherAwardsVestedTableTextBlock
Namespace Prefix: | rock_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of components of a stock option or other award plan under which equity-based compensation is awarded to employees, typically comprised of the amount of unearned compensation (deferred compensation cost), compensation expense, and changes in the quantity and fair value of the shares (or other type of equity) granted, exercised, forfeited, and issued and outstanding pertaining to that plan. Disclosure may also include nature and general terms of such arrangements that existed during the period and potential effects of those arrangements on shareholders, effect of compensation cost arising from equity-based payment arrangements on the income statement, method of estimating the fair value of the goods or services received, or the fair value of the equity instruments granted, during the period, cash flow effects resulting from equity-based payment arrangements and, for registrants that accelerate vesting of out of the money share options, reasons for the decision to accelerate. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of the number and weighted-average grant date fair value for restricted stock and restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock and restricted stock units that were granted, vested, or forfeited during the year. + References No definition available. + Details
Name: | us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the number and weighted-average exercise prices (or conversion ratios) for share options (or share units) that were outstanding at the beginning and end of the year, vested and expected to vest, exercisable or convertible at the end of the year, and the number of share options or share units that were granted, exercised or converted, forfeited, and expired during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ShareBasedCompensationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the weighted-average grant-date fair value of equity options or other equity instruments granted during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValueTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the number of fully vested share options (or share units) and share options expected to vest at the date of the latest statement of financial position, weighted-average exercise price (or conversion ratio), aggregate intrinsic value (except for nonpublic entities), and weighted-average remaining contractual term for both options (or share units) currently outstanding and options (or share units) exercisable (or convertible). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAndExercisableTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration