Share-Based Compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for future equity grants (in shares)	200,000
Total unrecognized compensation cost related to nonvested share-based compensation arrangements granted	$ 16,500,000
Weighted average period for recognition of unrecognized compensation cost	2 years
Weighted average grant-date fair values of options and weighted average assumptions used [Abstract]
Weighted average grant-date fair value of options per share (in dollars per share)	$ 7.29	$ 4.01	$ 5.94
Assumptions [Abstract]
Expected volatility (in hundredths)	53.80%	54.40%	53.00%
Expected dividends (in hundredths)	0.00%	0.00%	0.00%
Expected term	5 years 1 month 6 days	5 years 1 month 6 days	5 years 7 months 6 days
Risk-free rate (in hundredths)	1.90%	2.00%	2.40%
Shares [Roll Forward]
Outstanding, beginning of period (in shares)		4,689,000
Granted (in shares)	1,085,000
Exercised (in shares)	(1,077,000)
Forfeited (in shares)	(163,000)
Expired (in shares)	(209,000)
Outstanding, end of period (in shares)	4,325,000		4,689,000
Exercisable, end of period (in shares)	2,032,000
Weighted-Average Exercise Price [Roll Forward]
Outstanding, beginning of period (in dollars per share)		$ 15.65
Granted (in dollars per share)	$ 13.26
Exercised (in dollars per share)	$ 14.25
Forfeited (in dollars per share)	$ 11.34
Expired (in dollars per share)	$ 25.50
Outstanding, end of period (in dollars per share)	$ 15.09		$ 15.65
Exercisable, end of period (in dollars per share)	$ 19.21
Weighted-Average Remaining Contractual Term [Abstract]
Outstanding	6 years 4 months 24 days
Exercisable	4 years 3 months 18 days
Aggregate Intrinsic Value [Abstract]
Outstanding	13,182,000
Exercisable	3,992,000
Cash received from option exercises	12,748,000	2,835,000	4,825,000
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation	7,100,000	6,400,000	9,200,000
Total income tax benefit recognized	2,800,000	2,500,000	3,600,000
Share-Based Compensation Included in Cost of Services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation	2,900,000	3,000,000	4,100,000
Share-Based Compensation Included in Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation	4,200,000	3,400,000	4,500,000
Share-Based Compensation Included in Restructuring and Related Charges [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share-based compensation	0	0	600,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Aggregate Intrinsic Value [Abstract]
Total intrinsic value of options exercised during period	3,200,000	1,300,000	1,900,000
Tax benefit realized from option exercised	1,267,000
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	10 years
Nonvested Shares [Member]
Restricted Stock and Restricted Stock Units [Abstract]
Weighted average grant-date fair value of nonvested shares granted (in dollars per share)	$ 13.12
Shares [Roll Forward]
Nonvested, beginning of period (in shares)	1,013,000
Granted (in shares)	186,000
Vested (in shares)	(293,000)
Forfeited (in shares)	(65,000)
Nonvested, end of period (in shares)	841,000
Weighted-Average Grant Date Fair Value [Roll Forward]
Nonvested, beginning of period (in dollars per share)	$ 9.93
Granted (in dollars per share)	$ 13.12
Vested (in dollars per share)	$ 10.43
Forfeited (in dollars per share)	$ 10.15
Nonvested, end of period (in dollars per share)	$ 10.44
Restricted Stock and Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Restricted Stock and Restricted Stock Units [Abstract]
Weighted average grant-date fair value of nonvested shares granted (in dollars per share)	$ 13.12	$ 8.29	$ 13.26
Total grant-date fair value of shares vested	$ 3,100,000	$ 3,600,000	$ 7,400,000
Weighted-Average Grant Date Fair Value [Roll Forward]
Granted (in dollars per share)	$ 13.12	$ 8.29	$ 13.26