Summary of Significant Accounting Policies (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accounting Policies [Abstract]
Weighted average common shares outstanding for basic earnings (loss) per share	112,706	100,211	110,809	100,005
Dilutive effect of options and restricted stock units	350	16	471	450
Diluted weighted average common shares outstanding	113,056	100,227	111,280	100,455