Stock-Based Compensation - Narrative (Details) (USD $)	3 Months Ended		9 Months Ended			9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Stock Options	Sep. 30, 2014 Restricted Stock Units (RSUs)	Sep. 30, 2014 LTIP	Sep. 30, 2013 LTIP	Sep. 30, 2014 LTIP	Sep. 30, 2013 LTIP	Sep. 30, 2014 LTIP Minimum	Sep. 30, 2014 LTIP Maximum	Sep. 30, 2013 Board of Directors Restricted Stock Units (RSUs)	May 17, 2011 2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)															1,500,000
Award vesting period (in years)						3 years				3 years
Expiration period of options (in years)						10 years
Total compensation cost not yet recognized						$ 4,000,000	$ 10,200,000
Total Compensation Cost Not yet Recognized, Period for Recognition (in years)						1 year 5 months 19 days	1 year 6 months 27 days
Share-based compensation expense	2,600,000	400,000	8,700,000	6,200,000				700,000	(800,000)	1,200,000	(1,200,000)			300,000
Accrued employee compensation and benefits	$ 17,282,000		$ 17,282,000		$ 24,956,000			$ 2,800,000		$ 2,800,000
Multiplier for target award based on total shareholder return on common stock (percent)												0.00%	200.00%