Income Taxes Schedule of Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Deferred Tax Assets and Liabilities [Line Items]
Current deferred tax assets, compensation and benefits	$ 1,285	$ 1,935
Current deferred tax assets, accrued lease termination	1,582	1,313
Current deferred tax assets, other	754	753
Net deferred income taxes, current	3,621	4,001
Current deferred tax liabilities, prepaid expenses	(1,740)	(1,392)
Current deferred tax liabilities, compensation and benefits	(62)	(64)
Total current deferred tax liabilities	(1,802)	(1,456)
Net deferred income taxes, current	1,819	2,545
Long-term deferred tax assets, goodwill and other intangibles	147,968	108,122
Long-term deferred tax assets, compensation and benefits	33,254	22,031
Long-term deferred tax assets, foreign net operating losses	3,798	3,003
Long-term deferred tax assets, deferred rent	2,572	1,930
Long-term deferred tax assets, foreign tax credits	1,950	1,761
Long-term deferred tax assets, other	2,446	1,501
Long-term deferred tax liabilities, property and equipment	3,690	(611)
Long-term deferred tax assets, valuation allowance	(5,536)	(4,349)
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	186,452	133,999
Long-term deferred tax liabilities, goodwill and other intangibles	(21,330)	(17,190)
Long-term deferred tax liabilities, other	(93)	(372)
Deferred Tax Liabilities, Gross, Noncurrent	(25,113)	(18,173)
Net deferred income taxes, less current portion	161,339	115,826
Deferred Tax Assets, Net	$ 163,158	$ 118,371