Stockholders' Equity (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012
Accumulated other comprehensive loss	$ (8,724,000)	$ (8,724,000)	$ (12,781,000)
Additional paid-in capital recorded through compensation-related cost		750,000
Stockholders' equity		513,678,000	460,721,000	418,792,000	559,743,000
Comprehensive income		50,226,000	40,984,000	24,446,000
Acquisition-related stock issuance and adjustment	2,600,000	2,551,000	6,012,000	7,340,000
Acquisition-related stock issuance and adjustment, shares	288,884
Treasury Stock Acquired, Average Cost Per Share		$ 11.78	$ 10.92
Stock Repurchased During Period, Shares		1,601,906	234,300
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	8,400,000	8,400,000
Accumulated other comprehensive income (loss) related to interest rate derivatives	300,000	300,000
Chicago Partners LLC [Member]
Acquisition-related stock issuance and adjustment			5,800,000	5,800,000
Acquisition-related stock issuance and adjustment, shares			591,320	453,220
EthosPartners Healthcare Management Group, Inc. [Member]
Acquisition-related stock issuance and adjustment				$ 1,600,000
Acquisition-related stock issuance and adjustment, shares				187,846