Income Taxes - Pretax Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Line Items]
Income from continuing operations before income taxes	$ 36,038	$ 55,958	$ 50,234	$ 31,528	$ 32,315	$ 54,271	$ 44,504	$ 27,582	$ 173,758	$ 158,672	$ 169,506
U.S. [Member]
Income Tax Disclosure [Line Items]
Income from continuing operations before income taxes									138,616	122,517	131,722
Outside the U.S. [Member]
Income Tax Disclosure [Line Items]
Income from continuing operations before income taxes									$ 35,142	$ 36,155	$ 37,784