XML 83 R98.htm IDEA: XBRL DOCUMENT v2.4.0.8
Equity-Based Compensation - Weighted-Average Assumptions Used for Grants of Stock Options and SARs (Detail) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected dividend yield 0.00% 0.00% 0.00%
Forfeiture rate 10.31% 10.21% 11.50%
Risk free interest rate, minimum 0.02% 0.07% 0.01%
Risk free interest rate, maximum 1.78% 1.95% 3.18%
Expected weighted-average life 5 years 5 months 1 day 5 years 5 months 23 days 5 years 5 months 1 day
Fair value of stock appreciation rights (SARs) granted $ 4,528,000 $ 5,533,000 $ 5,495,000
Weighted-average grant date fair value of SARs granted $ 13.86 $ 12.84 $ 14.29
Stock Option and Stock Appreciation Rights (SARs) [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Volatility 32.00% 35.90% 35.33%
Risk free interest rate 0.82% 0.94% 2.01%