Condensed, Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 31,823,000	$ 36,321,000
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustment	(2,744,000)	1,064,000
Other Comprehensive Income (Loss), Net of Tax	(2,744,000)	1,064,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	29,079,000	37,385,000
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	1,338,000	1,076,000
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	27,741,000	36,309,000
Comprehensive Income Attributable To Redeemable Noncontrolling Interests	$ 711,000	$ 510,000