Income Taxes - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]
Deferred tax assets	$ 50,782,000	$ 26,594,000
Potential affect of unrecognized tax benefits on effective tax rate	3,000,000
Interest accrued on unrecognized tax benefits	1,200,000	2,400,000
Income Tax Benefit, Recognition of Previously Unrecognized Tax Benefits	6,000,000	3,100,000
Potential change in unrecognized tax benefits	2,600,000
Unrecognized tax deductions, share-based compensation		23,000,000
Tax benefit from share-based compensation expense	22,900,000
Excess tax expense of compensation plans	8,571,000		7,553,000
Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards	37,000,000
State
Income Tax Contingency [Line Items]
Net operating loss carryforwards	$ 246,000,000