Condensed Consolidated Statement of Changes in Stockholders’ Equity (Parenthetical)	6 Months Ended
	Jun. 30, 2018 shares
Condensed Consolidated Statement of Changes in Stockholders’ Equity
Issuance of common stock in connection with restricted stock unit awards, shares	1,048,639
Issuance of common stock for the employee stock purchase plan, shares	30,769
Shares withheld for net settlements of share-based awards, shares	409,431
Purchase of common stock for treasury, shares	282,980