XML 85 R71.htm IDEA: XBRL DOCUMENT v3.8.0.1
Incentive Plans (Narrative) (Details) - USD ($)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Unvested share-based compensation arrangements, compensation costs to be expensed $ 29,800,000    
Unvested share-based compensation arrangements, number of years compensation costs to be expensed 2 years    
Vesting scheme Under these plans, one-half of each grant is generally exercisable after two years and the remainder after three years.    
Total intrinsic value of options exercised $ 0   $ 200,000
Stock options exercised [1] 0 15,575 [1]
Related income tax benefit recognized in income $ 5,017,000 $ 15,244,000 $ 13,583,000
Share based compensation settled in cash 12,900,000 17,200,000 1,600,000
Incentive compensation plan expense $ 30,500,000 $ 25,800,000 $ 26,400,000
Share-based Compensation Award, Tranche One [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Vesting period 2 years    
Share-based Compensation Award, Tranche Two [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Vesting period 3 years    
Maximum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Option term 7 years    
2012 Long-Term Plan [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Long term plan expiration year 2022    
Maximum number of shares available for issuance 8,700,000    
Maximum number of shares available for issuance, annual rate 1.00%    
Number of shares available 2,600,000    
Employee Stock Purchase Plan [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Salary that can be withheld by eligible employee for stock purchase 10.00%    
Stock purchase price, percentage of the fair value of the stock 90.00%    
Employee Stock purchase plan, termination date The ESPP terminated June 30, 2017.    
Employee stock purchases, shares 2,564 8,962 8,387
Employee stock purchases, price per share $ 26.85 $ 23.41 $ 34.93
Compensation costs estimation Compensation costs related to the ESPP were estimated based on the value of the 10% discount and the fair value of the option that provided for the refund of participant withholdings    
Discount percentage 10.00%    
Fair value per share issued under ESPP $ 5.34 $ 2.94 $ 5.74
2012 Long-Term Plan and the 2007 Long-Term Plan [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Option granted to date, term of years 7 years    
2012 Long-Term Plan and the 2007 Long-Term Plan [Member] | Share-based Compensation Award, Tranche One [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Vesting percentage 50.00%    
Stock Options [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock-based compensation, fair value assumption model Black-Scholes option pricing model    
Stock options exercised     32,349
Stock Options [Member] | Minimum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Vesting period 2 years    
Stock Options [Member] | Maximum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Vesting period 3 years    
Employee Stock Options [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Stock options exercised 0 0  
Related income tax benefit recognized in income $ 0 $ 0  
Time-Lapse Restricted Stock and Restricted Stock Units [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Fair value per share at grant date $ 28.51 $ 17.57 $ 49.67
Performance Based Restricted Stock [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Vesting period 3 years    
Stock-based compensation, fair value assumption model Monte Carlo valuation model    
Performance Based Restricted Stock [Member] | Minimum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Fair value per share at grant date $ 24.10 12.21 44.03
Performance Based Restricted Stock [Member] | Maximum [Member]      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Fair value per share at grant date $ 28.28 $ 16.34 $ 48.12
[1] Shares issued upon exercise of stock options and award of restricted stock are less than the amount reflected in Note J due to withholdings for statutory income taxes owed upon issuance of shares.