Income Taxes Pretax Income (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income (loss) before income taxes	$ 32,315,000	$ 54,271,000	$ 44,504,000	$ 27,582,000	$ 28,120,000	$ 52,789,000	$ 51,683,000	$ 36,914,000	$ 158,672,000	$ 169,506,000	$ 158,711,000
U.S. [Member]
Income (loss) before income taxes									122,517,000	131,722,000	138,683,000
Outside the U.S. [Member]
Income (loss) before income taxes									$ 36,155,000	$ 37,784,000	$ 20,028,000