Income Taxes (Schedule of Components of Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current deferred tax assets:
Allowance for doubtful accounts	$ 1,997	$ 1,937
Tax credits	1,636	1,583
Other accruals	61,100	55,683
Total current deferred tax assets	64,733	59,203
Noncurrent deferred tax assets:
Tax credits	5,333	5,333
Net operating losses	1,180	2,077
Other accruals	59,176	58,605
Total noncurrent deferred tax assets	65,689	66,015
Total deferred tax assets	130,422	125,218
Current deferred tax liabilities:
Inventories	84,955	78,675
Total current deferred tax liabilities	84,955	78,675
Noncurrent deferred tax liabilities:
Property and equipment	131,851	132,547
Other	14,551	13,012
Total noncurrent deferred tax liabilities	146,402	145,559
Total deferred tax liabilities	231,357	224,234
Net deferred tax liabilities	$ (100,935)	$ (99,016)