Income Taxes Provision (benefit) for income taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Current Federal Income Tax Expense (Benefit)	$ 48,500	$ 77,400	$ 13,200
Current State and Local Tax Expense (Benefit)	2,080	1,949	1,000
Current Foreign Tax Expense (Benefit)	2,400	1,800	1,800
Current Income Tax Expense	52,980	81,149	16,000
Deferred Federal Income Tax Expense (Benefit)	(13,500)	(12,200)	11,400
Deferred State Income Tax Expense (Benefit)	(900)	(1,700)	2,406
Deferred Income Tax Expense (Benefit)	(14,400)	(13,900)	13,806
Income Tax Expense (Benefit)	$ 38,580	$ 67,249	$ 29,806