Stock-Based Compensation (Details) 5 (Restricted Stock Units (RSUs) [Member], USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2014
LTIP Plan [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Unrecognized compensation costs on nonvested awards $ 54,078
Unrecognized compensation costs on nonvested awards, weighted average period of recognition (in years) 2 years 6 months 22 days
Assumed Plans [Member]
 
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Unrecognized compensation costs on nonvested awards $ 16,275
Unrecognized compensation costs on nonvested awards, weighted average period of recognition (in years) 3 years 2 months 8 days