Shareholder's Equity (Narrative) (Details) (USD $)	0 Months Ended	3 Months Ended		0 Months Ended
	Mar. 03, 2015	Mar. 31, 2015	Mar. 31, 2014	Jul. 02, 2014	Jul. 16, 2014	Aug. 09, 2013
Common Stock:
Stock repurchased program authorized by the board of directors						$ 40,000,000.0
Mandatory Convertible Preferred Stock
Preferred stock dividends	2,300,000	2,264,000	0
Stock Incentive Plans:
Number of shares authorized for grant under share incentive plan		1,200,000
Shares available for future grants/issuance under stock incentive plan		773,718
Unrecognized compensation cost on non vested awards		24,900,000
Weighted average period		1 year 4 months 26 days
Number of units granted		295,527
Grant date value of common stock		$ 55.40
Stock Repurchased To Cover Employee Tax Withholdings [Member]
Common Stock:
Repurchase of common stock, shares		67,000	68,014
Repurchase of common stock		3,700,000	2,900,000
Stock Options [Member]
Stock Incentive Plans:
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years
Options term		10 years
Employees [Member] | Restricted Stock [Member]
Stock Incentive Plans:
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		4 years
Number of installments in restricted stock granted.		3
Mandatory Convertible Preferred Stock [Member]
Stock Incentive Plans:
Number of anti-dilutive options		3,200,000
Stock Options [Member]
Stock Incentive Plans:
Number of anti-dilutive options		0	0
Common Stock [Member]
Issuance of stock (in shares)				9,775,000
Issuance of stock, price per share				$ 45.00
Stock offering expenses				18,500,000
Mandatory Convertible Preferred Stock [Member]
Issuance of stock (in shares)				1,725,000
Issuance of stock, price per share				$ 100.00
Stock offering expenses				$ 5,900,000
Mandatory Convertible Preferred Stock
Dividend rate		5.25%
Initial liquidation preference (usd per share)		$ 100
Consecutive trading day		20 days
Dividends declared (usd per share)	$ 1.3125
Sheridan Healthcare [Member] | Common Stock [Member]
Common Stock:
Shares of common stock issued for acquisition					5,713,909
Minimum [Member] | Mandatory Convertible Preferred Stock [Member]
Mandatory Convertible Preferred Stock
Conversion rate		1.8141
Maximum [Member] | Mandatory Convertible Preferred Stock [Member]
Mandatory Convertible Preferred Stock
Conversion rate		2.2222
Performance-based Restricted Stock Units [Member]
Stock Incentive Plans:
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Number of units granted		68,945
Grant date value of common stock		$ 55.40
Performance goal period for vesting		1 year
Projected vesting percentage		100.00%
Performance-based Restricted Stock Units [Member] | Minimum [Member]
Stock Incentive Plans:
Projected vesting percentage		0.00%
Performance-based Restricted Stock Units [Member] | Maximum [Member]
Stock Incentive Plans:
Projected vesting percentage		150.00%