Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010 Y	Dec. 31, 2009
Goodwill and Other Intangible Assets
Gross Carrying Amount	$ 85,847	$ 5,854
Weighted-Average Amortization Period (in years)	15	7
Accumulated Amortization	6,853	2,895
Net Carrying Amount	78,994	2,959
Intangibles not subject to amortization
Goodwill	120,045	6,507	6,507
Trademarks	15,455	15,452
Total goodwill and other intangible assets	214,494	24,918
Changes in goodwill
Goodwill, gross, balance at the beginning of the period	21,932	21,932
Additions through acquisitions, gross	113,944
Goodwill, gross, balance at the end of the period	135,876	21,932	21,932
Accumulated impairment, balance at the beginning of the period	(15,425)	(15,425)
Additions through acquisitions, accumulated impairment	(406)
Impairment loss	(406)
Accumulated impairment, balance at the end of the period	(15,831)	(15,425)	(15,425)
Goodwill, net, balance at the beginning of the period	6,507	6,507
Additions through acquisitions, Net	113,538
Goodwill, Impairment Loss	(406)
Goodwill, net, balance at the end of the period	120,045	6,507	6,507
Aggregate amortization expense	9,599	2,598	388
Expected amortization expense on existing intangible assets
2012	8,638
2013	7,655
2014	6,785
2015	6,382
2016	4,920
Thereafter	44,614
Total amortization expense	78,994
Finite-Lived Intangible Assets
Expected amortization expense on existing intangible assets for the next five years	$ 78,994