XML 33 R16.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stock-Based Compensation (Text Block) | 12 Months Ended
--- | ---
Dec. 31, 2017
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract] |
Stock-Based Compensation [Text Block] | Stock-Based Compensation We maintain the Second Amended and Restated 2010 Stock Incentive Plan (Stock Incentive Plan), which allows us to grant stock-based compensation awards, including stock options, restricted stock units, phantom stock, and unrestricted stock units. Under the Stock Incentive Plan, we have 10,473,956 shares of common stock reserved and authorized for issuance subject to stock splits, dividends, and other similar events. At December 31, 2017, 4,656,327 shares were available for grant under the Stock Incentive Plan. We issue new shares of common stock upon the exercise of stock options or when vesting conditions on restricted stock units are fully satisfied. These shares are subject to a fungible share provision such that the authorized share reserve is reduced by (i) one share for every one share subject to a stock option or share appreciation right granted under the Plan and (ii) 1.7 shares for every one share of common stock that was subject to an award other than an option or share appreciation right. We also periodically award phantom stock units, which are settled in cash upon vesting and accounted for as liability-based awards with no impact to the shares available for grant. In addition, we maintain the ESPP, for which approximately 340,000 shares of common stock were available for future issuance at December 31, 2017. Unrestricted stock and ESPP activity for the years ended December 31, 2017, 2016, and 2015 was not significant. Stock-Based Compensation Expense Total stock-based compensation expense and the related tax benefit were as follows:
| 2017 |  | 2016 |  | 2015
| (in thousands)
Stock options | $ | 2,695 |  |  | $ | 2,357 |  |  | $ | 2,648 |
Restricted stock units | 17,738 |  |  | 14,723 |  |  | 10,735 |
Unrestricted stock awards | 974 |  |  | 955 |  |  | 706 |
Phantom stock units | 1,747 |  |  | 1,077 |  |  | — |
Total stock-based compensation | $ | 23,154 |  |  | $ | 19,112 |  |  | $ | 14,089 |
Related tax benefit | $ | 5,034 |  |  | $ | 4,927 |  |  | $ | 4,228 |
Stock Options A summary of our stock option activity is as follows:
| Shares |  | Weighted Average Exercise Price per Share |  | Weighted Average Remaining Contractual Life |  | Aggregate Intrinsic Value |  | Weighted Average Grant Date Fair Value
| (in thousands) |  |  |  | (years) |  | (in thousands) |  |
Outstanding, January 1, 2015 | 1,123 |  |  | $ | 51.90 |  |  | 4.4 |  | $ | 1,676 |  |  |
Granted | 291 |  |  | 35.25 |  |  |  |  |  |  | $ | 12.09 |
Exercised | (24 | ) |  | 36.05 |  |  |  |  | 26 |  |  |
Forfeited | (17 | ) |  | 37.47 |  |  |  |  |  |  |
Expired | (193 | ) |  | 52.17 |  |  |  |  |  |  |
Outstanding, December 31, 2015 | 1,180 |  |  | $ | 48.31 |  |  | 5.7 |  | $ | 405 |  |  |
Granted | 191 |  |  | $ | 40.40 |  |  |  |  |  |  | $ | 13.27 |
Exercised | (58 | ) |  | 37.00 |  |  |  |  | $ | 742 |  |  |
Forfeited | (36 | ) |  | 35.29 |  |  |  |  |  |  |
Expired | (318 | ) |  | 55.13 |  |  |  |  |  |  |
Outstanding, December 31, 2016 | 959 |  |  | $ | 45.64 |  |  | 6.6 |  | $ | 19,125 |  |  |
Granted | 135 |  |  | $ | 65.94 |  |  |  |  |  |  | $ | 21.99 |
Exercised | (41 | ) |  | 39.92 |  |  |  |  | $ | 1,071 |  |  |
Forfeited | (35 | ) |  | 47.38 |  |  |  |  |  |  |
Expired | (62 | ) |  | 70.12 |  |  |  |  |  |  |
Outstanding, December 31, 2017 | 956 |  |  | $ | 47.10 |  |  | 6.3 |  | $ | 21,965 |  |  |
Exercisable, December 31, 2017 | 640 |  |  | $ | 46.08 |  |  | 5.3 |  | $ | 15,934 |  |  |
Expected to vest, December 31, 2017 | 316 |  |  | $ | 49.17 |  |  | 8.4 |  | $ | 6,031 |  |  |
At December 31, 2017, total unrecognized stock-based compensation expense related to nonvested stock options was $2.9 million, which is expected to be recognized over a weighted average period of approximately 1.5 years. The weighted-average assumptions used to estimate the fair value of stock options granted and the resulting weighted average fair value are as follows:
| Year Ended December 31,
| 2017 |  | 2016 |  | 2015
Expected volatility | 32.5 | % |  | 33.5 | % |  | 34.3 | %
Risk-free interest rate | 2.0 | % |  | 1.3 | % |  | 1.7 | %
Expected term (years) | 5.5 |  |  | 5.5 |  |  | 5.5 |
Restricted Stock Units The following table summarizes restricted stock unit activity:
| Number of Restricted Stock Units |  | Weighted Average Grant Date Fair Value |  | Aggregate Intrinsic Value
| (in thousands) |  |  |  | (in thousands)
Outstanding, January 1, 2015 | 682 |  |  |  |  |
Granted | 434 |  |  | $ | 35.09 |  |  |
Released | (296 | ) |  |  |  | $ | 12,204 |
Forfeited | (64 | ) |  |  |  |
Outstanding, December 31, 2015 | 756 |  |  |  |  |
Granted | 306 |  |  | $ | 41.58 |  |  |
Released | (312 | ) |  |  |  | $ | 11,944 |
Forfeited | (49 | ) |  |  |  |
Outstanding, December 31, 2016 | 701 |  |  | $ | 38.04 |  |  |
Granted | 273 |  |  | $ | 50.95 |  |  |
Released | (372 | ) |  | 36.93 |  |  | $ | 14,219 |
Forfeited | (46 | ) |  | 48.56 |  |  |
Outstanding, December 31, 2017 | 556 |  |  | $ | 47.68 |  |  |
Vested but not released, December 31, 2017 | 142 |  |  |  |  | $ | 9,650 |
Expected to vest, December 31, 2017 | 350 |  |  |  |  | $ | 23,877 |
At December 31, 2017, total unrecognized compensation expense on restricted stock units was $21.7 million, which is expected to be recognized over a weighted average period of approximately 1.6 years. The weighted-average assumptions used to estimate the fair value of performance-based restricted stock units granted and the resulting weighted average fair value are as follows:
| Year Ended December 31,
| 2017 |  | 2016 |  | 2015
Expected volatility | 28.0 | % |  | 30.0 | % |  | 30.1 | %
Risk-free interest rate | 1.0 | % |  | 0.7 | % |  | 0.7 | %
Expected term (years) | 1.7 |  |  | 1.8 |  |  | 2.1 |
Weighted average grant date fair value | $ | 77.75 |  |  | $ | 44.92 |  |  | $ | 33.48 |
Phantom Stock Units The following table summarizes phantom stock unit activity:
| Number of Phantom Stock Units |  | Weighted Average Grant Date Fair Value
| (in thousands) |  |
Outstanding, January 1, 2016 | — |  |  |
Granted | 63 |  |  | $ | 40.11 |
Forfeited | (1 | ) |  |
Outstanding, December 31, 2016 | 62 |  |  |
Expected to vest, December 31, 2016 | 57 |  |  |
Outstanding, January 1, 2017 | 62 |  |  | $ | 40.11 |
Granted | 32 |  |  | 65.55 |
Released | (20 | ) |  | 47.02 |
Forfeited | (11 | ) |  | 40.11 |
Outstanding, December 31, 2017 | 63 |  |  | $ | 47.28 |
Expected to vest, December 31, 2017 | 63 |  |  |
At December 31, 2017, total unrecognized compensation expense on phantom stock units was $2.8 million, which is expected to be recognized over a weighted average period of approximately 1.7 years. As of December 31, 2017 and 2016, we have recognized a phantom stock liability of $1.7 million and $1.0 million, respectively, within wages and benefits payable in the Consolidated Balance Sheets.

X
- Definition The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -URI http://asc.fasb.org/topic&trid=2228938 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 50 -URI http://asc.fasb.org/subtopic&trid=2208855 + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationAllocationAndClassificationInFinancialStatementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration