Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2011

Commitments and Contingencies [Abstract]

Aggregate Minimum Commitments Under Non-Cancelable Operating Leases

Aggregate minimum commitments under non-cancelable operating leases, primarily for office space and equipment rentals, at December 31, 2011 were as follows (in thousands):

2012	$	18,589
2013		16,908
2014		15,165
2015		15,059
2016		15,285
Thereafter		71,717
	$	152,723