Stock-Based Compensation and Charges (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock-based compensation and charges
Total cost recognized for awards (in dollars)	$ 2,742,000	$ 1,996,000	$ 8,241,000	$ 5,856,000
Stock Options
Stock-based compensation and charges
Total cost recognized for awards (in dollars)	1,100,000	1,300,000	3,400,000	4,000,000
Restricted Stock
Stock-based compensation and charges
Nonvested shares outstanding	402,229		402,229
Aggregate grant date fair value of nonvested awards (in dollars)	3,200,000		3,200,000
Restricted Stock | Executive And Key Employees
Stock-based compensation and charges
Total cost recognized for awards (in dollars)	200,000	200,000	600,000	800,000
Granted (in shares)			0	100,000
Vesting period			4 years
Aggregate grant date fair value (in dollars)				700,000
Restricted Stock | Non Employee Directors
Stock-based compensation and charges
Total cost recognized for awards (in dollars)	100,000	100,000	300,000	200,000
Granted (in shares)			45,959	52,265
Vesting period			3 years
Aggregate grant date fair value (in dollars)			500,000	500,000
Time-vested restricted stock units
Stock-based compensation and charges
Total cost recognized for awards (in dollars)	1,300,000	400,000	3,800,000	800,000
Granted (in shares)			939,386	915,485
Vesting period			4 years
Aggregate grant date fair value (in dollars)			9,800,000	7,600,000
Nonvested shares outstanding	1,506,833		1,506,833
Aggregate grant date fair value of nonvested awards (in dollars)	14,500,000		14,500,000
Issuance of common stock, ratio			1
Time-vested restricted stock units | Tiger Lead Solutions, LLC
Stock-based compensation and charges
Granted (in shares)			273,420
Aggregate grant date fair value (in dollars)			$ 2,200,000