Stock-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Share-based compensation arrangement by share-based payment award
Common stock authorized for awards under 2003 Incentive Compensation Plan	13,500,000			13,500,000
Plan modification, incremental compensation cost	$ 185			$ 465
Weighted average exercise price per share
Options exercisable - weighted average exercise price (in dollars per share)	$ 10.27			$ 10.27
Stock Options
Share-based compensation arrangement by share-based payment award
Maximum term				10 years
Number of options
Options outstanding as of beginning of period (in shares)	3,461,000	3,461,000		3,461,000
Granted (in shares)	0	0
Exercised (in shares)	0	0
Cancelled (in shares)	(21,000)	0
Options outstanding as of end of period (in shares)	3,440,000	3,461,000		3,440,000		3,461,000
Options exercisable as of end of period (in shares)	1,302,000			1,302,000
Weighted average remaining contract term
Options outstanding as of beginning of period - weighted average remaining contract term (in years)	7 years 3 months 18 days	7 years 7 months 6 days				7 years 9 months 18 days
Options outstanding as of end of period - weighted average remaining contract term (in years)	7 years 3 months 18 days	7 years 7 months 6 days				7 years 9 months 18 days
Options exercisable as of end of period - weighted average remaining contract term (in years)	7 years 1 month 6 days
Weighted average exercise price per share
Weighted average exercise price of options outstanding as of beginning of period (in dollars per share)	$ 9.34	$ 9.34		$ 9.34
Exercise price of options granted (in dollars per share)	$ 0.00	$ 0.00
Exercise price (in dollars per share)	$ 0.00	$ 0.00
Weighted average exercise price of options outstanding as of end of period (in dollars per share)	$ 9.34	$ 9.34		$ 9.34		$ 9.34
Cancelled - weighted average exercise price (in dollars per share)	$ 8.90	$ 0.00
Aggregate intrinsic value
Aggregate intrinsic value of options outstanding as of beginning of period (in dollars)	744	659		659
Aggregate intrinsic value of options exercised (in dollars)		0
Aggregate intrinsic value of options outstanding as of end of period (in dollars)	7,912	744		7,912		659
Options Exercisable - aggregate intrinsic value (in dollars)	2,563			2,563
Compensation expense, tax benefit and unearned compensation
Stock-based compensation expense recognized (in dollars)	900		1,000	1,800	2,000
Tax benefit recognized related to stock based compensation expenses (in dollars)	350		380	710	760
Unearned compensation expense that will be amortized (in dollars)	5,700			5,700
Weighted-average period of amortization (in years)				2 years
Stock Options | Minimum
Share-based compensation arrangement by share-based payment award
Number of exercisable installments				4
Stock Options | Maximum
Share-based compensation arrangement by share-based payment award
Number of exercisable installments				5
Restricted Stock Units
Share-based compensation arrangement by share-based payment award
Vesting period (in years)				2 years
Compensation expense, tax benefit and unearned compensation
Stock-based compensation expense recognized (in dollars)	4,600		4,900	9,300	9,600
Tax benefit recognized related to stock based compensation expenses (in dollars)	1,720		1,870	3,480	3,660
Unearned compensation expense that will be amortized (in dollars)	$ 39,500			$ 39,500
Weighted-average period of amortization (in years)				2 years
Number of restricted shares
Unvested units as of beginning of period (in shares)	5,248,000	4,815,000		4,815,000
Granted (in shares)	85,000	1,354,000
Vested (in shares)	(70,000)	(918,000)
Cancelled (in shares)	(119,000)	(3,000)
Unvested units as of end of period (in shares)	5,144,000	5,248,000		5,144,000
Weighted Average Grant Date Fair Value
Unvested units as of beginning of period (in dollars per share)	$ 10.05	$ 10.53		$ 10.53
Granted (in dollars per share)	$ 10.48	$ 8.86
Vested (in dollars per share)	$ 9.94	$ 12.36
Cancelled (in dollars per share)	$ 11.51	$ 10.76
Unvested units as of end of period (in dollars per share)	$ 9.95	$ 10.05		$ 9.95
Restricted Stock Units | Minimum
Share-based compensation arrangement by share-based payment award
Number of exercisable installments				4
Restricted Stock Units | Maximum
Share-based compensation arrangement by share-based payment award
Number of exercisable installments				5
Chief Executive Officer | Restricted Stock Units
Share-based compensation arrangement by share-based payment award
Plan modification, percentage of bonus earned				100.00%
Executive Officers | Restricted Stock Units
Share-based compensation arrangement by share-based payment award
Plan modification, percentage of bonus earned				50.00%
Other Executives | Restricted Stock Units
Share-based compensation arrangement by share-based payment award
Plan modification, percentage of bonus earned				25.00%