Income Taxes (Schedule of Components of Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current deferred tax assets:
Allowance for doubtful accounts	$ 1,937	$ 1,933
Current tax credits	1,583	541
Other accruals	55,683	55,209
Total current deferred tax assets	59,203	57,683
Noncurrent deferred tax assets:
Tax credits	5,333	4,605
Net operating losses	2,077	3,008
Other accruals	58,605	50,855
Deferred tax assets - noncurrent	66,015	58,468
Total deferred tax assets	125,218	116,151
Current deferred tax liabilities:
Inventories	78,675	59,673
Total current deferred tax liabilities	78,675	59,673
Noncurrent deferred tax liabilities:
Property and equipment	132,547	138,132
Other	13,012	9,200
Total noncurrent deferred tax liabilities	145,559	147,332
Total deferred tax liabilities	224,234	207,005
Net deferred tax liabilities	$ (99,016)	$ (90,854)